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C^A T A L O G V S

eorum,

in hdcfecmddparte cmtinentur.

FRANCISCI a SCHOOTEN Principia Mathefëos Vniverfalis, feu Introduélio- ad CartesianjE Geometrie Methodum. Confcri^taabERAsMio Barth on No.

FLORIMONDI DE BEAVNE duotraöatuspofthu-* mi. Alter de Natura amp; Conftitutione, alter de Limitibusnbsp;.£(juationutn.

lOHANNIS DE WITT de Elementis Curvarum li-nearumlibriduo.

FRANCISCI a SCHOOTEN Tra^atus de con-cinnandis Demonftrationibua Geometricis ex Calculo Alge-braïco.

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LECTORI BENEVOLO

I. H V D D E S. P.

INGalliiseramcumcpiflralse meae imprimerentur, ideoque domumredux, onus in me fufcepi omnia de integro revidendi amp; ad calculum revocandi,nbsp;ut probe mihi conftaret, num quaedam nimis obfcurè expreflaciTent, velnbsp;etiam errata irrepfiflent; Qusecunque inveni, ilia funt quas fequuntur.

Ad clarioretn fenfum.

p.4141.1 ƒ. Kucipto 8cc. Cum x—a 00 o, multiplicatur per bc, refultat ix—cx—lt;ié-4-/»c00o,feua:0Onbsp;nbsp;nbsp;nbsp;_*¦;fi ponasjam c00o,non fequitur

valorem a: per hancaequationem non poiTe inveniri, quandoquidem Nominator tt b — « f per i —• c, dividi poteft, fed turn fequitur cum Nominator per Deno-minatorem non dividi poteft,vel cum ambo pereandera quantitatem indivifibi-lesfunt: Notandum ergo eft Denominatorem hie confiderari iine relatione adnbsp;Kominatoremgt; veluti patet ex iequentibus , i°. Obfervandum nenit nmnejuf-tnodi (fuantitates in aqmtitne reperiantur amp;c. zo, y? reperimtur, num utra-mque tequa-tionem dmidant. Sedhatc omnia fortaflis clarius ficintelligentur. Excepto tantum fi sequationis primus terminus non afFediusquantitate cognita iit ab unanbsp;parte, reliqui, qui ab altera funt, faciant fraftionem , cujus Denominator, velnbsp;Denominatorisdiviforaliquis, Nominatorem dividat, quod licontingat, vi-dendum eft, priufquam concludatur non dari duarum tequationum communemnbsp;aliquem diviforem, num etiam altera aequatio per hunc Denominatorem , velnbsp;Denominatoris diviforem aliquem, divifibilis fit. p. 4j'9.1.1 o. vel fic lege, aequa-tio ilia Temper indivifibilis erit per a;,xa,gcc., ^ » vel per x x,«?,«lt;!,amp;c.,nbsp;fc-—quantitatequaviscognita atquerationali. 0.461,1.19. ^roomnesifuantitatesnbsp;pone omnia membra. p.49i, I.i j. pronbsp;nbsp;nbsp;nbsp;feribeMethodo. p.4fi 8c45'6,l.i.

lege, nullus terminus eft oo o. p. ƒ00, in medio, pro Gltmiam tme Y C. ex l r

y^ln— -‘y f extrahipotirit j feribe, extrahendo |/ C.ex ir Y^rr_

Zx.’pto, fed cum YC ire., ufquead, liceat é'cy, pone, fedcum-j/C. ex bino-mionumeraliopeRegulsep.jS? ,yel perfeftèextrahi queat, velvulgariraodo praeterpropter, quod lufficit, poterit etiam ejufdem beneficio radix ex sequationenbsp;Propofita five numerali, fire literali fit, inveniri, cum pro literis numeros, vel o,nbsp;adarbitriumalTumere liceat. p. ƒ01,1.31. amp; p. ƒoƒ,1.17. rfflf»«hicfumiturpronbsp;xedigi ad duas alias, exquarummultiplicatione Propofita sequatio producipo-;teft. Errata, quae irrepferunt, inveniuntur inter errata primse partis.

Nec tacerefas eft me, non fine admiratione, in Epiliolis meis, qux tam fedu-bm typothetarum operam requirebant, tam paucos errores oftendifle, nifi cogv-tarem D. Elzevirios amp; Clariflimum Schotenium totis viribus huic operae incu-builTe, quapropter nullus dubito quin reliquum totum opusaccuratiusimpref-lum fit, quam quisfortaftlsexfpedaijret.

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A R M E

IN L A V D E M

F R.

S C H O O T E N,

Mathematicorum ocelli.

^Cotenl cum firipta legis , fe promit ubique ^ Ingenii mira dexteritate vigor.

^um vitam ac mores fpeEias, fe prabet ubique SpeBandam integritas, ac fine fraude mantis.nbsp;Sic qu£ perraro concurrunt corpore in uno,nbsp;Hicjungi ingenium cum probitate vides.

Ad de quod, ingenium cum fit Juperabile paucis, Vix tarnen invenies in probitate parem.

n E p I'

4gt;PArKl'sKOT SKnTH'NOr,

«TO fAetKAglTH f

MetB-hffïcos, E'ucrtCttctff

Tl^ xXeuHC^^psTt^ssS'T» nbsp;nbsp;nbsp;Ot 7^

1X870 nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;Mat^.

Vf/jEÜiïïC/jj) nbsp;nbsp;nbsp;Xgü4t hei^etc.

M, ^KOCT-Uo^ J E. nbsp;nbsp;nbsp;M. 'S.KXA'vlw®*'^ O'cfbmfiT sistf/, «K8 571» lt;/UKgOftgt;V lt;tXit j

KH-\,Ayov dvSpui

Xgy!r«s nbsp;nbsp;nbsp;;

’^.KOö'rUiJOi'-^'Ttf/.o'icny ^Aiias-i lt;^tkn9Uf H’^Ts pi’ -uzZTÉg TTOfTWV .CtpTÉ^i/XMCTÏ ©gflpv*

O'cïTo^y ^g’^TCgavj cuei lt;faÓ7Jast a-HO-•reivop

'XvfJLfXVlt;^liy nbsp;nbsp;nbsp;HetTAf Ivt a-KÓ7iï l

ax.i'Ta KéiTUj , Trdffjy /Wigo^W/

H’ f ««r^HTet y.i\ei.tYa,vu 'oj-no‘y^etfji.A-gt;

Tt tiilt;TU

Qv/Asi^nc juot i^os ATreoKiroy lt;;gt;8g7lt;t’7@' dvtfjimy

0‘ nbsp;nbsp;nbsp;/ui^iTAirHYoeniuLut»

Tov ^aIclCoóv Agt;iyd^Yov\yHVAlo i tqvt* y-et^lLuj

ASDgt;(si 9-01 nbsp;nbsp;nbsp;Cfc^iFOOV

Kftf figycv TTKn'rletf euh Aoc tdVov gt; Q7IWG0C (to ‘Trdhltj Ttt^

TrotnoTtifiilw

OV7«tv ihjj Wv7«v vitXu fislitAg ^lt;c*

H-difim)

TaIIw Kiv^lt;rea/At f eLKtvarov 7np iSffzutf AüTwgóVtóCj lt;croar)vnbsp;Au'Tiieizhf}^ jutjuv(»j vffltgvjjnbsp;MviifJiA 7iik06igt;ii6CH Ttdajv

vfxgoc

Ldn^uui ^lAyauf fis lt;^cL^ tiuS^t

fcé’w,

ït’2!L’ojy/to/OTpolt;A/fx«t7fltJT»V-'

lt;TA]i yaubxj,

KttQjiA fjLt^dffipoJfy,^ AvdMAvyk^ lt;oV Elf^aS-’ y AfWfg thjj fjLi^oTrm fia^vsnbsp;v) ^ÖOOf)

O vr» tffij Hit lt;q)}f yeti A xk^iS tcxj 0»«


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1

P R I N C I P I A

MATHESEOS

VNI VERS ALLS,

S E V

ÏNTRODVCTIO

A D

geometri^e methodvm

RENATI DES CARTES,

Confcripta ab

Er. Bartholino, Casp, Fil.

Editio tertLty prtore correSlior,

SSTJS

t/tMSTELODAMlf

ExTypographia Blaviana.mdclxxXiiï.

Sumpibus Societatis.

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Generis ^ ‘virtutmn Nohilitate Perilhfiri ^ Generofo Heroï,

D.CHRISTIANO THOMA,

TOPARCHi£ IN STAVGARD, Equiti Aurato, Sereniffimge Regiae Majeftatisnbsp;Cancellario Magno , Regni Daniae Senatorinbsp;primario, Regiae Academias Hafnienfis Con-fervatori fummo, Patuono incomparabili.

On minus verb quam ele^ ganter Cicero lib. i. Tufc.nbsp;quazft. Magni, inquit, efinbsp;ingenii re^ocare mentem aJen-^nbsp;Jïhm, ^ cogitationem a conjue--tudine ahducere. Cum enim mens noftra,nbsp;quam in nobis conclufam circumferi-mus, divinaquasdamparticulahabea-tur, nihil lane illi gratius accidere po-teft, quam, chm contemplando a cor-poreis rebus laxatur , originique fuaenbsp;quam fimillima redditur. Senfuum

* 2 nbsp;nbsp;nbsp;quippe

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E P I S T o L A

quippe ufura non minus fruuntur bru-ta animantia, qukn homines, imo, qu^edamlongè nobis pr^eftant j mentenbsp;verb quia non gaudent, univerfamnbsp;hanc mundi machinam , quafi tabu-lam piólam afpiciunt, nee cogitantnbsp;qua de causa quóve modo tot varie-tates rerum fint ordinatse. Quicun-que igitur hominum non cupiunt fe-metipfos private bono, quo reliquanbsp;animantia excedunt, non temerènbsp;permittent fefe fenfuum judicio itanbsp;mancipari-, ut ea fufficere putent,nbsp;quae manibus quafi palpare pofllmt,nbsp;ac pauca velint fi non oculis omniumnbsp;obvia 5 pauciora credant quee fenfusnbsp;non approbant, amp; pauciffima eligant,nbsp;nifi ab experientia firmentur. Nonnbsp;equidem diffiteri poffumus, hoe pro-pofitum utile efle atque necelTarium,nbsp;ut initio juvetur cogitatio noftra amp;c

intel-

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DeDICATORIA.

intelledlus ; unde faótum eft ^ quöd Geometrie figuras, Arithmetici nu-merorum chara(fteres , aliique alianbsp;fubftdia invenerint 5 Sed experimen-tis ejufmodi vix acquiefcere debentnbsp;magna ingenia, nee poteft is, qui fa-pientise Famam affeeftat. Communisnbsp;enim experientia docet, multa facilenbsp;mereri mentis alTenfum , amp; efle ve-rilTimaj etiamfi fenfiium judicio pronbsp;veris non agnoftantur : Sc vice versa , fenfus xjuaedam approbare 5 quae,nbsp;quia falfa , ratio nullo modo admit-tere poteft. Atque hxc licèt omnibus in confeffo unt, non defunt tarnen, qui nihil nifi Praxin amant es,nbsp;Theoriam amp;: fpeculationes omnes o-dio profequuntur, atque ut inutilianbsp;eliminant; quos pertinaci^e fuas ferönbsp;nimis poenitebit, cum aliorum impe-rio ita fubjedi efle coguntur, ut ne

3 nbsp;nbsp;nbsp;in

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E P I S T o L A

in Praxi quidem folita obftacula re-movere fciant, nee unquani novi quiequam addifcant , niii quod velnbsp;cafus ipfis, vel aliorum humanitas fup-peditaverit. At alii, quorum animusnbsp;longius exfpatiatur, amp; demonftra-tiones caufasque inquirit, utilia mul-ta inveniunt , quae ab aliis ignoran-turj adeoque in Praxi multa excogi-tantes compendia ^ allaborant ut tag-dia amp; impedimenta obvia tollantur jnbsp;quorum tarnen inventa non effentnbsp;repudianda , etiamli humani ingeniinbsp;imbecillitas ^ aut ufus raritas ^ ea fta-tim ad praxin revocare prohiberet,nbsp;Hinc non contenti do6tiores iis, qusenbsp;a Geometris aut Arithmeticis demon-ftrata atque inventa funt, quasquenbsp;ufus dudum confirmavit, nifi velnbsp;ipfas demonftrationes penetrate ^ eaf-demque invenire poffint j adeoque

^ fuper-=

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Dedicatoria.

fuperfl.ua refcindere, defèótus fupple-re , amp;: deperdita rettiüuere queant. Neque enim exiftimandum eft , ma-jores noftros omnem poftcris pracri-puifle materiem, qua excolatur inge-nium ; cum contra focordise meritönbsp;nos, incufarent, fi plus temporis innbsp;fcriptis luis etiamnum intelligendisnbsp;irnpendi, quam ipfl in incognitis in-veniendis pofuère ^ viderent. Ad quaenbsp;invenieiida cüm non alia via, (quantum conftat) quam quae per compo-fltionem 6c refolutionem procedit^nbsp;uterentur , quaeque naturalis potiusnbsp;ingenii facultas aut induftria ^ ufu 6cnbsp;exercitatione potita, quam ars certisnbsp;legibus 6c pr^ceptis contenta, dicinbsp;meretur j Recentiores artem quan-dam excogitarunt, quam vocant A-nalyticam, cujus principia tradit hoenbsp;opufculum. quae poftquam innotuit.

Ion-

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E P I S T OLA

E P I S T OLA

longè plura amp;c majora, quamabAn-tiquitate nobis reliólaÉunt, inlucem prodiére. Non patitur tempus amp; lexnbsp;fcribendi, ut commemorem, quanta ex hac arte, non tantum ad Arith-meticam , Geometriam , Mechani-fed etiam Opticam aliasque

cam

fcientias manaverint emolumenta. Nihil enim fani antehac de vifu novi-mus 5 cum omnia hie , heut in aliisnbsp;artibus, quai materia immerfas, nonnbsp;abftrahuntur a fenfibus, ad diredtio-nem mentis, dilputationibus hue il-luc trahebantur 5 jam omnia deter-minata , omnia demonftrationibusnbsp;munita. Qni enim in Opticis non plane hofpites funt, fat feiunt, quam in-certa , quamque defeduofa fuerintnbsp;ea ^ quas de Refradtionum legibus an-tea novimus, amp; quam falfa ilia deter-minatio figuras vitrorum, (de quibus

Dio-

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DeDICATORIA.

Dioptrica agit) qua nihil jam nabis optaripoteftperfedius, nihil certius.nbsp;fed de his forfan alias. ld mihi in prx-fens fufficit, hanc artem hbi proprionbsp;jure vendicare non foliim ea, qu^ denbsp;Mathefeos utilitate, deque Arithme-ticse, Geometrias, Aftronomi^, amp;nbsp;Muficae prieftantia , tot rationibus,nbsp;totvoluminibus, totque feculis dióiranbsp;funt, fed multb plura 5 quod facilenbsp;demonftrare poffem , nih plurimis,nbsp;qui hajc penitius introfpicere dignan-tur^ notum id fore fcirein. Nee opusnbsp;mihi eft, multa coram Te, Heros Per-illuftris ^ de hujus artis totiusque Mathefeos utilitate dicere : quoniam,nbsp;dum animus tuus magna lemper 6cnbsp;excelfa meditatur^ Mathematicas et-iam fcientias coluifti 6c amplexus es,nbsp;nihilque Tibi ad fapienti^ comple-mentum deeffe voluifti. Sed malo de

# nbsp;nbsp;nbsp;He-

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Ep I STOLA

Heroicis amp; eximiis tuis virtutibus tacendo, publicum omnium teftimo-nium implorare , quam in prsefensnbsp;pauca dicere. Ars fane Analytica per-fpedtum habet, cujus viri prsefidiumnbsp;expeélat j cum implorat tuum : neenbsp;enim Daniae unquam, quamdiu Ma-thefis aliaeque artes, liberales tales in-venerint Patronos, vel virtus vel fa-pientia deficiet. Patere igitur, Herosnbsp;Perilluftris, nomini tuo Principia hxcnbsp;inferibi, amp;c fruótum inceptse peregri-nationis fereila fronte accipe. Tui e-nim nominis clypeo munita, frontemnbsp;audent obvertere hoftibus , quibusnbsp;feculum hóe abundat, quiquè varianbsp;tela in obvios effundere non veren-tur 5 prout affedus malevoli ipfis di-dtaverint. Solent plerique, qui roderenbsp;amant, objicere ^ pervulgata omnianbsp;effe 5c ex aliis defumpta 5 qua eenfura

quam-

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Dedicatoria.

quamquatn fciam hoe fcriptum non polTenotarij tarnen pr^fagit animus,nbsp;fore, ut hxc tanquaminutilia amp;: nimisnbsp;curiofa rejiciant. Si enim intellexe-rint 5 hoe ambitu, etiam Algebramnbsp;compleóiii, faftidio commoti ^ fubtili-tates ejus cane pejus amp;: angue fu-gient. Sed vix metuet fibi Ars Ana-lytica a talibus hoftibus, nam, cumnbsp;aoóliffimis quibusque Mathematicis,nbsp;quibus feeulum hoe quad fuperbit,nbsp;probetur, de reliquis ipfi minus eftla-borandum: nee ulla alia hu jus Me-thodi defendo requiritur, nid quamnbsp;experientia, amp; ipdus rei intelledsenbsp;ufus attulerit. Et, ut verba in paueanbsp;conferam, d tuo exaftifdmo limatif-dmoque judicio probentur , nulliusnbsp;in pofterum cenfuram aut notam per-timefcent. Neque ego exilitate ope-ris deterritus, fed contra utilitatepo-

^^2 nbsp;nbsp;nbsp;dus

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Epistola Dedicato'ria.

tius inftigatus, Tibi hxc confecra-re fiim verims : amp; quidem tanta ma-jorefiducia, amp; fpe certiore, quanto certius mihi conftat Te omnibus m,nbsp;qui inter bonas artes etiam Mathe-maticis incumbunt, favere ; quemnbsp;favorem quotidie familia nofhra fen-tit , amp; grato animo femper recolit.nbsp;Vale regni Danix decus , èc xqai bo-nique confule hoe grati animi monu-mentum, quod humillimè offert

DevotifTimus amp; obfêquen-tiffimus diens

Erasmius Bartholinus.

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lectori s.

^ Vm omnes fapientes audire velint, amp; nihil tarn temerarium tamque indignum fapientü gravitate atque conftantia fit, qudmautfialfiumfien-tire, aut quod non fiat is exploratumJitfime ullanbsp;duhitatione defender e: neficio quofatofiat, quodnbsp;non operam dent ejufinodifiudiorim viam ingredi,qud mensnbsp;adfiieficat uerum dfaljis ^ dubiis diflinguere. fifiiandoqui-dem enim d teneris adfiieficere multum efi, egregiè fibi con-jiderent, fi ad Mathefiin excolendam ab ineunte atate ani-mum appellerent. Mathematicas autem dificiplinas hancnbsp;pra aliis habereprarogativam, vix dubitaripot efi, modbnbsp;confideretur, quicquidIn iis concluditur amp; determinatur,nbsp;idomne expramijjis necejjitate quadamfiequi, vel verum,nbsp;veldubium, velfalfium, prout priemijf£ variis modisfie fienbsp;babuerint: Adeo ut, etfinon aliis ujlbrn infierviret Mathe-fis , tarnen vel hoc nomine, ad fiui cognitionem trahere deberet etiameos, quibm nullum aliud ex eajperaretur emolu-mentum. ^uod cum abundè obfiervatum amp; uju comprobatumnbsp;fit d Veteribus, quos plerique nofir a at ate it a fufipiciunt ^nbsp;venerantur, ut majm quoddam animo complexi, plus mul-to etiam vidifie videantur, qudm quantum nofirorum inge-niorum acies intueri pot efi y inter alia mirari fiubit, omnesnbsp;fere, exemplum illonm hac in re deferuijfe. ^ippe comper-tumefi , antiquosThilofiophos nonpermififfe,nbsp;ficholasjuas ingredi, ut ad Sapientiafiudiumadmitteren-tur, quique ante non haberent hccQdi lt;ptMi^(picts. ^odnbsp;fanepropofitum, non rationeprudentius, qudm eventufie-licius fiuit: cum hancfiuijfie caufam, quod ad illampertige-rint jcientiam, quampofieritnstantoperemiratur, IS quonbsp;virtute fiua nonnulli eniti fie pojfe defiperant, conjiciam.nbsp;Frufira enim fipeliatur firullus dificiplinarum, ab eo, quinbsp;earum altitudinem non metitur; nec in cacumen evadere

Ptefi,

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Pr^fatio

potejl, qui non folerter rimatur viam, ^ aditiis, qui eo ferunt, negligit. Mat he fa autem, cum ex notionibmfim-plicijjimis, cognituqtie facïÜimis, ad dïfficiliora, atquere-motijjima qiiteqiie cognojcenda far ducat juniores, qui faa-concefais opintonihm vacui non impediuntur varietate re~nbsp;rum, qu£ animüfaovehfiorum iiiharent y non dubito, quinnbsp;fitaa tener is imbuatur mens, ad aliarum quoque rerum,nbsp;maximè comfafaarum atque ohfcuriorum, cognitionem fanbsp;fenetratura.Et quoniam Mathefa variis fartibm confiat,nbsp;qu£ omnes circa quamitatem verfantur y res d 7tDjirijeculinbsp;Ltminibm eb redaamp;a eji, ut generaliter ill£ omnes trail art , amp; quantitas h£C in univerfali amp; abflraÜo far lite~nbsp;ras Alphabeti concipi pojjit. Ita enim,fa£ld ad omnes quan-tit at is fpecies afalicatione, intelleitm ratiocinando adva-rias res inveniendas diftinSlè progredi fatefl. Toflquam autem Methodus illa diu latuit, teiia verborum involucris,nbsp;cum quibm prim luBandumerat qudmfruUm ullus fpe-raripoterat; opportune nobis Nobilifamm Tgt;. Bdes-cartes,nbsp;infaperabilis ingenii Vir (qui, reclusd d fe, baBenm inco-gnitd, ad ver am fapientiam vid ,poJt tot feculorum fxdif-Jimam fervitutem, omnibm imitando exemplo, ita natur£nbsp;myfteriapandit, ut ver£ fapienti£fludium, hiimanarum-quefcientiarum encycloptedia dr perfeBio, immaturd ejusnbsp;ac deplorabili morte, majorem nunquam jaituramfacerenbsp;potuerit) earn ad hanc facilitatemperduxit, ut, quoddifficult at is reliquum efl, nonalidratione qudmjiudiolèdili-gentiaevincipojjit. Taceo hic perfeBionem, adquamresnbsp;Mathematic as hujm Methodi fubjidio redegit: cum ipfa-rum tejlimonia tion tantum invit os laudumque fuarumde-trailoresinillispalmam ei dare cogant, fedetiamquouf-que, hunianummgenitm in iifdemprogrediquidvepr£jia-revaleat determinent. Vcrüm enimvero cum omnium ma-gnarum rerum faut arborum altitudenosdeleBet, ^radices

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Ad L E C T o R E M.

dices Jlirfefque non item : Jic multi ad Jumma pervenire oftarent, nifi in elementis har ere opus haberent. atqui,nbsp;quemadmodum illa altitudo fine radicibm ,ftirpibufque ejfienbsp;non poteji; it a ilU fruftra fe in idfafligium recipi fperant,nbsp;quibus cordi non eji fundamenta jideliter jacere. Et cumnbsp;antehac non edit afint ulla principia, qua ad adita hujusnbsp;Methodi ducerent; quidmirum ?Jimuiti in ipfio limine ha-fiitaverint ^plurefiqiie, qiios, re inexpertd, defiperatio infiu^nbsp;gum averterit. Etemim nee hujus Methodi Aublor, nee Tgt;o-^ijfimi ejus Comment at or es d fiemetipfisimpetrarepotue-f'unt, nt bonos horos, quos fiubtiiioribus, invent is dicave-^ant, in edendis, qua ^pm ad hanc Methodum fternerent,nbsp;impenderent. Cumitaque nihil hac in re , omnibus votis,nbsp;tam d me ipfio olim, qudm d muit is hodie expetita , prafti-tum ejfe repererim: diu multumqne inter fipem metumnbsp;harens, dolui, tamdiu inter tot Mathematicoriim monument a ea deftderari,qua adficientiarum increment a emun-Ctioris naris homines necefiarib requiri jampridem cenfiue-ruttt. Ego fianè opportunitate mira, ante aliquot annosnbsp;voti campos faBus,poftquam ad hafice or as Academiam 11-luftrem, qua Leida ejl accejfifi'ir Celeberrimus atque E)o-Bijfimus Francificus d Schooien, Mathefieos ibidemFro-fejfior publicus , me Artem Analytic am, haneque Methodum , tam eximiia fide docuit, ut adperfeölionem nihil mi-hi prater ingenium proprium induftriam defuijfie cre-diderim. fiftpocirca fepofitdprivati commodi a (lima t tone utnbsp;plures felicitatis hujusparticipesfiacerem, amp; quapropriisnbsp;ufibus deftinaveram , publici juris redderem, de elementis hïfice, quibus inter alia imbutus er am, evulgandis, co-gitareeoepi. Etlicètvererer ne amicitia jura, quainternbsp;nos cumfido fiemper fiervari opt al am, hac ratione viola-nem ; tarnen facilem mthi veniam fiperabam , fi non ni-Ji ojficiofia fraude fallerem qua gloria ejus, qui fie bono

publico

-ocr page 20-

fublico ml devovit, ceder e, nee alias magis an'mum meum gratum tejiari jgojfet.nbsp;nbsp;nbsp;nbsp;neprimas quidem fpesfortuna

defiituit: quippe abipfo, qui nullum erga me beuevolenti£ pignrnatqueindiciumomittit, nonmodo veniamhiijmzeilnbsp;impetravi, fed ^ eamhumanitatem, ut omnia perlegerenbsp;amp; examinare baud gravatus fuerit, lucemque ingenii ^nbsp;eonfiUiJuiporrigere. Operis brevitatemquod attinet, nonnbsp;ejt, quam difplicere cuipiam putem: fquidem copiam exem-plorum, quibus ad dijcendum nihil aptius, nullus (ut opi-nor) hk defderabit s in quibus apferendis ejujmodi dele~nbsp;Plus eji obfervatut, ut, quoad fieri potuit, in mediumad-ducerentur ea, quavelinipfo AifijMre, vel in ejus Com-mentatoribm reperiuntur: qua ideofpar firn ita Junt difipo-fita , ut, meo judicio, nonaliol' comeliüsintelligi, fmul-quepradiSiis lock illuflrandk infervirepotuerint, in quemnbsp;finem, in margine paginartm citationem additam ejfe ap~nbsp;parebit. ^yddeb ut, quicunque tantum Arithmetica Species , cum in integris, turn in fraPlkperdidicerit, leviquenbsp;numerorum irrationalium notitid inflruplus , in allatisnbsp;exemplk accurate examinandk fefe exercuerit, fie non in~nbsp;utiliter tempus, ubi ad Geometriam’D’'‘ 'Des-Cartes ac-eejferit, confumpfiijfe experturus fit. ^immb vtdehit ja-nuam referaat am omni ei, quod ab Algebra ep Anaptfi Geometrie a ex fpePlari pot efi: ideoque fé MathefeosVniver-falk confiitutionem animo comprehendifie. neque enim exi-Jiimo, hifice int e lie Elk, operapretiumfore, Algebra vul-gark cognitionem amplius exoptare , licèt leviorem ejusnbsp;notitiam, velipfe T). 'Tgt;es-Cartes, antehac, adfua Geo-metria Methodumintelligendam , requifiverit. Vale.

PRIN-

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Celeberrimi de Centro Ofcillationis proble-matis folutio.

Viro Sapientifllmo falutcm dat

STEPHANVSGILLET,

Nulla in re tarn irrito conatu laborarunt Viri Clarifflmi, quam in centre ofcillationis invefiigando ; licet enimnbsp;quadraginta abhinc annis mathematictis Celebris nus~nbsp;quam gentium extiterit uUm, qui huic indagationi ac-curatijfme baud incubuerit, quin etiampluriminbsp;audadier exclamarint y nullos tarnen in error es inciditnbsp;nullus. Na ego aliena infelicitate minim exterritm,nbsp;viam adeo exfeditam invent, ut adfcofum opatum reBenbsp;prvenerim. §^o circa arbitror tibi rebus mathematic Is gaudenti non ingrafum fore, fi hoc arcanum taii~nbsp;topre invefligatum exhibuero-

Centri ofcillationis dcmonftratio.

I. nbsp;nbsp;nbsp;‘Definitio.

' Scillatio eft ipfa agitatio’penduli ftia I gravitate circa axem horizonti pa- ^nbsp;irallelummoti. V. G. Si pendulum, ^

^Ajfuam agitationemvigravitatis in-cipiatinpundio jW. inhibeatque inpundto v. ipfa agitatio hujuspcn-duli totum arcum (av. percurrentis vocatur ofcillatio.

II. nbsp;nbsp;nbsp;‘Definitio.

(^orum pcndulorum centra gravitatis arcus nbsp;nbsp;nbsp;'y

fimiles percurrunt, eademfuas ofcillationes,

fimUesfaciunt, licutpendulaAamp;^. nbsp;nbsp;nbsp;......

III. nbsp;nbsp;nbsp;TdSefinitio.

Centrum ofcillationis eft punftum, quod in pendulo compofito sgitato perinde movetur, ac ft nuilo modo ftipatum foret: ac proinde

^ nbsp;nbsp;nbsp;fiin

-ocr page 22-

fiin extremo pendali fimplicis reflderet, ofcillatiönes fuaseodem tempore conficeret,atque pendulum compofitum datum. Itaque totanbsp;difKculcasIiuc recidit,ut inveniatur longitudo penduli fimplicisjquodnbsp;fuas ofcillationes fimiles eodem tempore conficiat, atque pendulum compofitum datum: nam longitudo hujus penduli fimplicis ea-dem eft, atque diftantia centriofcillationispendulicompofitiab axc.nbsp;Qiia in inveftigatione ut mens dirigatur, aliquid de gravitate, fpatio-quc decurfo prjemittendum eft.

I. nbsp;nbsp;nbsp;Lemma.

Gravia gravitatem habcnta levioribus, qu£e taatumd^mafcen.^ dunt, quantum graviora defcendunt.

ï. Coroll-

Hinc colligas mobili fecundumhorizontemraoto gravitatem ac-* quiri nullam: Quia nullalevioraafccndunt.

II. nbsp;nbsp;nbsp;Coroll.

Hincanimadvertismobili circa c^trum moto gravitatem acquiri nullam: ideo qüod mobile baud magis deprimitur, quam extollitur»,

III. nbsp;nbsp;nbsp;Coroll.

Hinc vides gravitatem- acquiri per folam defcenfionem centri: quippequi aliimotus pronihilo liabeantuc; ac proinde incidentiananbsp;gravis femper efle fpedtandam ex altitudinc defcenfionis centri.

IV. nbsp;nbsp;nbsp;Coroll.

Hinc perfpicis duorumgravium exeadem altitudine cadentium, quorum unum perpendiculariter, alterumnbsp;vero oblique decidit; utriufque velocitatem eandem eflenbsp;in liorizontCjfive in plano horizonti parallelo: proptereanbsp;qnod gravitas per motum vel circa centrum,vel horizonti parallelum, neque intenditur, neque remittitur.

V. Coroll.

Hinc manifeftumeft velocitatem gravis penfilis, fi-* ve penduli eandem efle, atque gravis ex eadem altitudi-dineperp. decidentis: penfileenim nihil aliud eft, quamnbsp;grave oblique dccidsns.

VI . Cö-

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VI. CoroU.

Hinc clarum eft eandem effe velocitatem in omnibus pendulis quorum centra gravitatis sque diftant ab axibus, quandoquidemnbsp;ïcqualiter defcendunt.

VIL CoroU.

Hinc liquet eandem efle velocitatem ejufdem plani turn in planum, turn inlaiusmoti: utpotequodcentrum utroque modotequedepri-matur.

• nbsp;nbsp;nbsp;II. Lemma.

Duobus gravibus ex cadem altitudine cadentibus, quorum unum perp. altcrum vere oblique fecundum reétam lineam detidit j Tempora utriusque incidentitefunt inter feficututraquelineafecundumnbsp;quas inciduntj quandoquidem eadem eft velocitas in utroque mobilinbsp;tequalitcr defcendente.

CoroU.

Hinefequitur ut duobus gravibus ex eadem altitudine fecundum. fingulas lineas redtas oblique cadentibus j Tempora utriufque inci-dentiaeinter fereferantur, ficututraquelineaobliqua, velficutfpa-tiadccurfa, fi gravia fint asqualia.

III. Lemma.

Si planum indefinite dividatur in panes aliquotas. Summa produ-«ftorum fingularum partium per fuam ab axe diftantiam multiplicata-rum, ïqualis eftprodufto totius plani per fuicentriab eodemaxc diftantiam multiplicati.

X

A

y

ft/\

/aa\

/m\

/yw-/

vv

k

’ m\/s.a

\aa/\a^/\aii/

!aia\ //oa\/öit'

Sit planum (AB) indefinite $-divifum in partes aliquotas {aa), ex quibus fingulis dimittanturnbsp;fingulas lines inter fe parallels,nbsp;esqueadaxem 0^ extrapofitumnbsp;perpendiculares, qus vocenturnbsp;j; linea c plani centro ad eundcra

axenj

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axem perp. du(Sa appclletur x : dico fummatn omnium produdo-rum, a aj/, efle aequalem p roduélo a lgt;x.

Namque plani ita divifi fingulï partcs perindc fpeótari poffunt, ac fiforent lingula pondera: at ex geoftatica fumma produdorum lin-gulorum ponderum per fuam ab axe diftantiam multiplicatorum, ae-qualis eftprodudo omnium ponderum per centri communis abco-dcm axe diftantiam multiplicatorum j Ergo amp;c.

I Coramp;ll

Hinc perfpicuumeft fummam prodmftorura fingularum partium ejufdem plani multiplicatarum per fingulas periplierias, quarumfe-midiametri funt ipf* perpend, ad axem, cfle aequalem produdo totiusnbsp;plani multiplicati perperipheria m , cujusferaidiametereftipfadi-ftantia centri ab axe.

II. nbsp;nbsp;nbsp;CoroU.

Hinc patet fpatium a plano in planum circa axem extra pofitum moto decurfum, aequari produdo iplius plani multiplicati per peri-pheriam, cujus femidiaraeter eft diftantia centri ipfius plani ab axe.

III. nbsp;nbsp;nbsp;Coroll.

Hincultro emergitinvcftigatio omnium folidorum aplaniscirca axes motis defcriptorum j fed ifticc alibi.

IV. nbsp;nbsp;nbsp;Coroll.

Hinc deduces fpatium a plano in planum circa axem extra pofitum moto decurfum, £Equarialteri fpatio, quod percurreretur fifingulanbsp;pun6ia,vel fingulae panes aliquotse plani tantumdem ab axe diftarent;,,nbsp;quantum ipfius centrum gravitatis.

V. nbsp;nbsp;nbsp;Coroll.

Hinc apparet fpatia a planis aequalibus decurfa, efl'e in eadem ratio-ne, atque eorumdem planorum diftantias centrorum gravitatis ab axe,

V r. Coroll.

Hinc nullo negptio reperias fpatium a plano in latus moto de-curfum:

Si

-ocr page 25-

A

k nbsp;nbsp;nbsp;/

m/—

Si'enim planum A indefinite dividatur per fuperficies cylindra-ceasparallelas, quarum omnium fit idem axis 6 ^: conficiatur planum , by cujus fin-guls lines axi parallels squentur fingulis feftionibus B-cylindraceis , qusnbsp;tantumdem ab axenbsp;diftantjV. G. lineanbsp;redaMN.squeturnbsp;feftioni. ^ ficquenbsp;decsteris jexhu/iisnbsp;plani ^Centrolinea

ad axem Ö § perp. duéla vocetur Z : ex plani A centro linea perpend. duSa ad eundem axem appelletur , x. Spatium a piano A in planumnbsp;eft adfpatium ab eodem piano in latus moto decurfum, ficutar. x..nbsp;nam fpatium a piano A in latus moto decurfiam, squatur fpatio pernbsp;planum b in planum motum decurfo.

lam vero centrum ofcillationis colluftrctur.

I. Troblem.

Invenire centrum ofcillationis plani in planum circa axem extra pofimm moti.

Centrum ofcillationis idem eft, atque centrum gravitatis ipfius plani.

J

V ^.........

/J

l\ L-......

f-.-, nbsp;nbsp;nbsp;1

gt;

Cum enim, ex 6'°corollarioprimi lemmatis, amp; ex 4'’coron. 3'“ lemmatis, planum A eadem velocitatc , idem fpatium pcrcurrat,nbsp;quod percurreret fi ipfius omnia punfta tantumdem ab axe diftarent,.nbsp;quantum centrum gravitatis j necefie eftutofcillationes fuas eodemnbsp;tempore perficiat, atque pcrficerct fifingula punda tantumdem abnbsp;axe diftarent; atqui fifingulapunda tantumdem ab axe diftarent,nbsp;ofcillationes fuas eodem tempore conficeret, atque pendulum fim-plex , cujus longitudo eft ipfa diftantia ceatri gravitatis ab axe.nbsp;Ergo amp;c.

T nbsp;nbsp;nbsp;I. O-

-ocr page 26-

I. nbsp;nbsp;nbsp;QorolL

Htnc novcris omnium planorura, quorum centra gravitatis algt; axe aeque diftant, idf m cfl'c centrum ofcillationis in planum.

\\. Coroll.

Hincintelligis cujullibet lineae in planum circa axem extra pofi-tum motae, centrum ofcillationisidem cfle, atquecentrum gravita-tis; Quandoquidem quaelibet linea fpcdari poteft., ficutplanum mi-nimse latitudinis.

II. nbsp;nbsp;nbsp;Trobl.

Invcnirc durationem ofcillationis plani in latus circa axem extra politum moti.

Tempora ofeillationum plani turn in planum, turn in latus moti, funt inter fe, ficut fpatia utroque motudecurfaj propterea quodu-triufque ofcillationis tempora perinde fpedanda funt, atque tempora incidcntiarum duorum gravium xqualium ex eadem altitudinenbsp;oblique decidentium.

III. nbsp;nbsp;nbsp;Trobl.

Invenirc centrum ofcillationis plani in latus circa axem extra po-fitum moti.

Si centri plani ab axe diftantia vocetur x. tempusque ofcillationis in planum, fit ad tempus ofcillationis in latus, ficut x. z.-. hujus

relationis x^. nbsp;nbsp;nbsp;: at. -5 . ultimus terminus defignabit diftantiam cen-

tri ofcillationis ab axe, fivelongitudinem pendulifimplicis, quod fuasofcillationesfimileseodcm tempore conficit, atque pendulumnbsp;in latus motumj propterea quod longitudines pendulorum fimpli-cium funt inter fc, ficut quadrata temporum ofeillationum.

IV. Trobl.

Invcnirc durationem ofcillationis folidi.

Si folidum A , indefinite dividatur per fuperficies cylindraceas pa-rallelas, quarura omnium idem fit axis, atque ofcillationis j coin-

pona-

-ocr page 27-

ZN

ponatur planum ^,cu-* jus fingulas linear axinbsp;parallelar , fint internbsp;le,ficutfingul3E fectio-nes cylindraccje, quxnbsp;lantumdem ab axe di-ftant.. Diftantia cenr-tri hujus plani ab axe

vocetur z.. diftantiac^ue centrl folidi ab eodem axe appclletur Xi. Tempus ofcillationisiblidi, eft ad tempus ofcillationis pendtili fim-plicisjcujus long!tudo fit x. Iicut2,.x. quandocjuidem folidum fpe-(ftari debet ficut planum in latus motum.

V. nbsp;nbsp;nbsp;Trobl.

I'nvenire centrum ofcillationis folidi.

Hoc problema perinde folvitur , atque 3. prob. fupra.,

VI. nbsp;nbsp;nbsp;'^robl.

In venire centrum ofcillationis peripherise in latus circa tangen-tcm motsE.

Diftantia centri ofcillationis ab axe, five longitudo penduli fimpli-CIS ofcillationes fuas eodem tempore coiificientis,refertiir ad radium, ficut quadratoquadratum diametri ad producftum circuli per fe ipfumnbsp;multiplicati j (^andoquidem fpatium ofcillatione in planum eft adnbsp;Ipacium ofcillatione in latus decurfum, ficut circulus ad quadratumnbsp;diametri, ut ex infinitorum geometria demonftratur.

VII. nbsp;nbsp;nbsp;Trobl.

Componere pendulum quod ofcillationes fuas eodem tempore conficiat ,atque pendulum ft mplex datum.

Longitudo penduli fimplicis dati fit diameter peripheriae, quam axisnbsp;tangit in pundlo O. fi hac in peri-pheria bina punda A amp; Bapundonbsp;fufpenfionis teque diftantia ad libitum fumantur; liaec duo punda component pendulum,quod fuas ofcillationes in latus eodem tempore con-ficict, atque pendulum fimplex. adnbsp;quodprobandunv

-ocr page 28-

3

f gt;

Wxc duo punöa llnea diametrum perp. fecante in punéto D. jun^ gantur, fcótio diametri D O, vocaturx. linea A O fiveBO appel-letur^-

£x fupra diöis tempus ofcillationis in planum,eft ad tempus ofcil-lationis in latus ficut x.Tiy ac proinde hujus relationis nbsp;nbsp;nbsp;~ .

ultimus terminus five diameter defignabit longitudinem penduli fim-plicis, quod ofcillationes fuas eodem tempore conficit, atque pendulum ex iftis binis punÖis compofitum, in latus motum.

CorolL

Hinc tibi confeftim occurrunt infinitapendulacompofita, qu» fuasquodque ofcillationes eodem tempore conficiunt: verumhaudnbsp;fcioanobitiipefcasquodperipheria fuas ofcillationes breviore tempore perficiat, quam pendulum firaplex, cujuslongitudo eft ipfanbsp;diameter , cum peripheria integra refolvi polïitin pendula fimpli-ciora componentia, quorum fingula fuam quodque ofcillationemnbsp;eodem tempore feorfim conficiant; mirari tarnen defines fi perfpexc-ris majorem elTe gravitatem in peripheria conglutinata , quam innbsp;omnibus ipfiuspartibus disjundim motis.

VIII. Trobl.

Invenire durationem ofcillationis cujuflibet penduli circa axera intrapofitummoti.

Si pendulum A, cu-jus diftantia ab axe voce-tur X. indefinite divi-

daturper fuperficiescylindraceasparallelas, quarum omnium idem fit axis, atque ofcillationis: componatur planum B, cujus fingulas li-neasaxi parallela: fint inter fe , ficut fingute feóiiones cylindracese,nbsp;qu3E tantumdemabaxe diftant; diftantiaque centri planiBab axeap-pelletur z.-. Tempus ofcillationis penduli A, erit ad tempus ofcillationis penduli fimplicis, cujuslongitudo fit ar, ficut 2:. ar.

FINIS.

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P R I N C I P I A

MAT HES EOS

VNIVERSALIS, •

s E F

INTRODVCTIO

A D

GEOMETRIiE METHODVM

RENATI DESCARTES.

LOGISTICA OVANTITATFUsimplicifm.

• nbsp;nbsp;nbsp;V M in omniScientia, ad difficiliorum rc-rumcognitionem, uüle fit a fimpliciffimisnbsp;amp; cognkufacillimis órdiri; baud inconfiil-

• nbsp;nbsp;nbsp;tum t’ucrit, ad generalem atque facilemnbsp;comprehenfionumMathematicarum Scien-

; ciarutn, quje omnes circa quantitatém ver-fantur, ad ea primum attendere, quae noti ^é, aliquam ejus fpeciem excludere, fed eas,nbsp;quocunque fe habeant modo , fub certis notis cuique ob-viis reprsfentarc poflint. Vnde cum in univerfanbsp;nbsp;nbsp;nbsp;vide np

Scientiarumconftitutione, licèt diverfaobjcftarefpiciant, non nifi relationes five proportioncs quxdam , quae in iis reperiun-^^’^'^j^^®'nbsp;tur, confiderentur ; confentaneum eft rationes atque propor-ficunda.nbsp;tiones illas fcorfim ipeöare , easque literis Alphabet! , utpo-te notis fimpliciflicnis nobisque cognitiffimis , infignire. Ne-que enim ratio ullacft, quo minus per a, byC, amp;c. concipian-tur magnitudinesnbsp;nbsp;nbsp;nbsp;c, amp;c. quam pondera aut numeri iif-

dem characleribus defignati. Attamen quia tum phantafiae tum fcnfibus ipfis, nihil fimplicius nee diftinftius exhiberi poflè oc-currit, quam reöa; linete, qu^que relationes amp; proportiones,nbsp;quae inter omnesalias res inveniuntur, exprimere valent: prae-PmlI.nbsp;nbsp;nbsp;nbsp;Anbsp;nbsp;nbsp;nbsp;¦ fiat

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j nbsp;nbsp;nbsp;Principia

ftat per praediiflas literas folummodo lineas rcflas conclperc. Hinc li du3e fuerint quantitates defignatse per lt;3 amp; ^, inteliigenturnbsp;peripfas duae difFerentes lincae reöïe, diverfasfcilicet longitudi-nis: itautper^intelligatur longitudo feuquantitas unius, amp; pernbsp;b longitudo feu quantitas alterius. Non fccus atque perlt;ïamp;lt;ï,nbsp;aut per b ^ b duas intelliguntur linea: aequalesj nifi indicaverisnbsp;fuppofuerifve^Jeircaequalem ipfi^, vel4amp; ^ejufdemeffe valoris,nbsp;idquodficdenotaturlt;3 GO Et fic de aliis.

Cum autem non raró occurrat, ut linea aliqua fit aliquoties fu-menda, oportet tantum numerumconvenientemipfi literseprx-figere: Vtaddefignandum, lineamlt;3eflebisfumendam, fcribo 2 a. Sic amp; ad defignandum duplum, triplum, quadruplum amp;c.nbsp;ipfius^, fcribo 2^, 3 ^,4^amp;c. Nee aliter fitfi ad defignandumnbsp;femiffera, tertiam aut aliam quamcunquepartem linea:fcri-

baturi^ï,amp;c. idquodetiamhocpadlofierifolet jamp;c. fic amp;duastertias,tresquartas,amp;c. ipfius^,itadefignaveris\b^\b\nbsp;vel fic, ^~ gt; atque ita de aliis.

lam cum in univerfa Mathefi operationes omnes ad quinque diverfas ( vulgó Species didias ) reduci pofifint, qu£E funt Additio,nbsp;Subtraéiio, Multiplicatio, Divifio, amp;: Radicum extradio; confe-quens eft ut oftendatur, qua ratione did«e operationes per literasnbsp;fint inftituendse.

T)e AMitïone quantitatum

Gitur ad addendum lineam a ad lineam fcribo pro fumma 2 ^: fic amp; ad addendum 2 ^ ad 3 fcribo 5 b. Lines enim eif-demliterisfidenotantur, oportet tantum numerosprsfixos ad-dere, amp; fummam eidem liters prsfigere. Si veró diverfs fuerint,nbsp;additio fiet interpofitofignoq-, quod denotat plus. Vtfi ad lineam ü fit addenda linea fcribo lt;* , hoe eft, ^ plus ^, quo in-dicatur b eflc additam ipCia, vel adhuceife addendam. Vbipa-tetdidumfignumfemperefle referendum adfequentem literam,nbsp;feu qus priori addi debet.

Nee aliter fit, fiplures in unam fummam funt colligends. Vt ad addendum 2 b,b, 8c ^ b, fcribo Sic amp; ad addendum a,b,8c c,nbsp;fcribo ^ c.

jExm*

-ocr page 31-

Matheseos' Vniversalts.

Exem^la additionis fmplicium.

Add.lt;'‘*-1 a.

Summa z a.

zb

2 A

3d.

A

3 A

d.

3 b.

5A

4d.

6 A

a.

a.

3

b.

2 b.

qd.

c.

a zb.

3 £'4-4d.

^ h'

T iilt;jicmuuiii,in auditione literarumfi amp; 3 4, cogitandumel-feliteram d fibipr$fixam habere unitatem; idcjiiodetiaminfe-cjuenti exemplo amp;fimiUbus eft obfervandum; utamp;, cumpUi-rcs adduntur diverfe literse, perinde effec^uo ordine fcribaiitur, ^, vel ^

T)e SuhtraBione quantitMum Jïtn^licium.

T Am Verb ad fubtrahendum lineam 2 ^ a linea 5 a, fcrlbendum 3 fiquidem lines, cjus iifdem Ikecis hint defignats, fub-ducuntur, fubtrahendo tantum a feinvicem numcros pisfixos.nbsp;Sic ëcÜ2 auferantur a 3 reliquum erit i ^ feu b. Similiterfub-lato d de 4 d, relinquitur 3d: Kt a Ac a manet o feu nihil.

Quod fi verb lines diverfis literis notats fuerint, fubduAio fiet interpofito figno —, quod denotat minus. Vt fiab a fubtra-hendafit^, fcribo4'—^, Koe eft, 4 minus ^, quo indicator ^ effenbsp;fublatamex4,yeladhuceflfefubducendam. Vbipatet diöumfi-gnum femper efl'é referendum ad fequentem literam, hoe eft, qusnbsp;cx priori eft fubtrahenda.

Eodemmodo, fublatis 4 d ex 3 c, reliquum erit 3 c—4^.

Exempla JubtraBionis

Ex f 4. 3 A 4 d. a. Ex 4. nbsp;nbsp;nbsp;3 c. 4.nbsp;nbsp;nbsp;nbsp;2 c.

fubtr. 2 4. xb. d. a. fubtr. A qd. 4 A d.

teliq. 3.4. A 3d. o. reliq. 4—A 3^—qd, Oij^b. ic—d.

Vnde notandum, in ejufmodi quantitatum fubtradione, opor-tere quantitatem illam, qus cx alia fubtrahi debet, eftc minorem:

A 2 nbsp;nbsp;nbsp;hoc

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4 nbsp;nbsp;nbsp;PRINCIPIA

hoceft,adfubtrahendum^exrf, (utinfuperiorlexemplo) opus cffe, ut ^ fit minor qakma. Quödfiautem non proponacur aucnbsp;conftet, utra quantitas fit major aut minor, amp; tarnen fubdudionbsp;fieri debeat j differentia earum denotari poterit hoc modo:nbsp;nbsp;nbsp;nbsp;^ ,

hoceftjA—b yó.hat.

De AlMj^licatione quantitatPtm fimplicium.

POrro admultiplicandumlineam^perlineam^ , fcribolt;i^ vel ba. Sic amp; ad multiplicandum a per a, hoc eft, in fe, fcribonbsp;a a feu ^:Sgt;caaa feu a^ ad pracdidlum produétum a a adhuc femelnbsp;multiplicandum per a. Adeo ut liters immediate fefe coiifequen-tes, multiplicationem earum per invicemfaébam, vel adhuc fa-ciendamefle, indicent. Nonfecus, fi multiplicare velima,bdi cnbsp;per invicem, fcribo4vel vel amp;c: amp; a bb[eaab^ velnbsp;b’- a, ad multiplicandum 4, b, amp;c b. Hic enim, ut in additione, nonnbsp;refert, quo ordinefcribantur.

Quemadmodum veroexdudualicujusnumeriinfe, idquod producitiir vocatiir Quadratura ejufdcm numeri,amp;: fi produduranbsp;illtid adhuc femel per eundem numerum multiplicetur, produ-dus numerus appellatur ipfius Cubus, atqueita deinceps^ itanbsp;quoque fi 4 multiplicetur per 4, produdum aa feu4‘appcllarinbsp;confuevit 4 quadratum, feu a duarum dimenfionum j amp; fi4 4 rur-fusmultipliceturper4,producetur444feu4t, quodideo appct-laripoteric4cubus, feu4crium dimenfionum: atqueita a‘*, 4%nbsp;a^,8ic. dici poterunt a quadrato-quadratum, 4 furdefolidum,nbsp;4 quadrato-cubus, amp;c. feu, 4habens 4, 5, aut 6,amp;c.dimenfiones.

Sicuti autem numerusaliquisjfi in fe ducatur, dicitur radix qua-drataiftius produdi feuquadrati: amp;fi adhuc femel per hoe pro-duclum multiplicetur,turn radix Cubicahujus pofterioris produ-di appellatur, amp;cjficamp; 4 dicitur radix Qiiadrata ex 4 4 feu 4* ,amp; radix Cubica ex4^, amp; radix Quadrato-Quadrataex4“*, amp; radixnbsp;Surfolida ex a’’, amp; radix Quadrato-Cubica ex a'^, atque ita por-ró. Idemde reliquiseftintelligendum.

Ex quibus conftat diligenter elfe notandum, quod magnum fit difcrimen inter aliquam quantitatem, cui numerus aliquis prasfi-xus eft, amp; inter eandem quantitatem, ubi idem numerus a tergonbsp;cft adferiptus. Vtinter 2 4 amp; 4% 3 4 amp; 4*, 44 amp; 4^*, amp;c. fiquidena

per

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Matheseos Vniversalis^ S per i 3nbsp;nbsp;nbsp;nbsp;amp;c. fimpliciter intelligitur quantitaslt;jbis,ter,

quater, amp;c. funipca,hoc eft,4fibiipfi toties addita; atverö per(j% amp;c. Quadratum, Cubus, Qiiadrato-Quadratum, amp;c.nbsp;ipfius (J, hoe eft, ipfa quantitas a toties pofita amp; multiplicata.

Exem^la multifile ationisJimplicium.


Multipl. a. per b.nbsp;produSumT^.


an

a


ah

c


a a. nK a he.


ah

h

abb.


ah

cd


aa

ah


abed, a'' b.


Vbi notandum in ^, produdlo multiplicationis quantitatum a a amp; ah, numetum ternarium quantitatem prsccdentetn re-fpicere, non autenafequentem h’. quod,’cumbrevitatis causaferi-batur '^ïQaaab f in omnibusfimilibus cafibusquoque eft intelli-gendum. Eadem ratione, ad multiplicandum a^^ hoc eft, lt;« a pernbsp;a} izMana, ^xoducciar a^i\iote^i,aaaaaa.

Quod fiquantitatesoccurrant multiplicands, quibus numeri, five integri (ivc fradli prsfiguntur, oportebit didtos numeros innbsp;feinvicemducere, ut in vulgar! Arithmetica, amp; eorum produ-öum prsfigere produifto , quod exfurgit ex multiplicationenbsp;quantitatum diftarum. Vt ad multiplicandum zlt;«per3 b; mul-tiplicatis 2 per 3, provenit6^,quodliprsfigaturipfilt;?^, produ-Ö.0 quantitatum a h per invicem, erit qusfitum produdlumnbsp;€ah. Similiter multiplicatis 2 ^per c, produdtum erit 2 ^c. namnbsp;nnitas, qushic ipfieprsfigi fubintelligitur , duftain 2, pro-ducit 2.

Necaliter fit, fi ad multiplicandum ^ ah j hoc eft, tzx ah per zed, hoc eft, bis c lt;sf, feribatur 6 abed. Sic amp; , multiplicatis '-a anbsp;peri4^, hoc eft, femift'eipfius a a pertertiam partem ipfius 4^,nbsp;produétumfiet ^«3 hoc c^^^aaab.


Exempla multiplicationis.


Multipl. 2 per 3 b


zb

e


\d


-^ab 2 ed


.aa


3 b^


6 a^.


produft. ibe. iad. 6abed. ^a^b. z^a^b^. 44*.

Vbi tandem feiendum, quod licet ex multiplicatione produ-cantur quantitates pluriumdimenfionumfeu literarumj earum

A3 nbsp;nbsp;nbsp;tarnen


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6 nbsp;nbsp;nbsp;Principia

tarnen additioncm atquc lubtraftioncm non aliter fieri atque prxcedentium. Vtadaddendum 2lt;*^ad 3 «ï/ijfcribitur 5nbsp;nbsp;nbsp;nbsp;amp;

ad addendum (? lt;1^ ad 2 ^ c, fcribitur 6^ ^ 2 ^ c. Non fecus, ad fubtrahendum zahAc^ab., fcribitur lt;3^: amp; ad fubtrahendutnnbsp;2 b cèQ6ab y fcribitur 6a b— 2 Et fic dealiis.

De Di’vifione c^uantitatum jtm^licium.

Voniam vero divifio refolvit id, quod multiplicatio compo-* ^nit: facile apparet, ad dividendain quanticatem lt;ï^-fcu banbsp;per a, opus tantum effe ex quantitate dividenda a b tollere quan-titatem a, qus divifor eft, amp; pro quotiente fcriberc reliquaranbsp;quantitatemEodemmodo,fidividatur^^per^,orieturlt;3; amp;nbsp;^(3iïfeu^ï’per^, orietur«2lt;i. Nonfccusdivisa^^cper^j, fiet^c:nbsp;at per fiet a c: amp; per c, fiet 4 b.

Quód fi veró quantitates dividendje occurrant, quibus numeri fint praefixii oportet, fadladivifione quantitatum, utjaniofteii-fum eft,fimilitcr diflos numeros dividere, ut in Arithmctica vul-gari, amp; quod oritiir invento quotienti quantitatum prsfigere.

Divid.4^

per a Divid. 6ab'


Exem^la divijïonüJimplicium.


'^b quot.


gt;aa.


abt


d^b I

'abC'


•aa.


aa


Cüm autem occurrunt quantitates dividendte, ex quibus lite-ras diviforispraecedentimodo tollinequeunt; fubfcribitur Divifor ipfiDividendo interjedalincola, admodumfradionis Arith-

a h

rneticaï vulgaris. Vtaddividendum^^perc, fcribo —, quo in-* dicatur 4 ^eflè divifam per c, vel adhuc effe dividendain. Sic amp; adnbsp;dividendiim4perfcribitur^. fimiliterdivisa^i^cperi5fe,quo-

tiens erit . amp; fic de aliis. Quse quidem quantitates fic divife appellantur Fradiones.

Eft vero bic obiter notandum, divifis 4 per 4,2 ^ per 2 b, fimi-libufvc, quotientem elfe i: fiquidem qusevisquantitas feipfam femel continet, ideoque per feipfam divifa, unitatemprofert.

DE


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Matheseos Vniversalis. 7

BELOGISTICA QVANTITATFM COMPOSITARVM.

¦p* Xplicata Simplicium quantitatum opcratione , qijoniam ex ¦*^illarum additione amp; fubtradione oriunturquantitates, pernbsp;fignuniH-compofitse, autperfignum —disjuncts, (quaeconi-muniter generali nomine Compolitse dicuntur); confequens eft,nbsp;ut harum quoque operationem deinceps oftendamus,

uddditione quantitatum com'^ojttarum.

T Gitur ad addendum quantitates Compofitas, iifdemliterisno-.tatas, oportet confiderare figna amp; —, quibus afficiuntur, 8c notare, fi cadem fuerint, additionem fieri ut in fimplicibus, amp; ea-rum fumma: prsfigi idem fignum. Vt ad addendum a 3 ^ ad lt;*nbsp; 2^: additislt;*ad^, amp; 3 ^ad 2 fummaerit 2 lt;« 5 égt;. Eodemnbsp;modo za’—^^additumad 3 ^— 3nbsp;nbsp;nbsp;nbsp;facitfummamnbsp;nbsp;nbsp;nbsp;— 4^.

Quód fi verb figna diverfa fuerint, fubtrahendae erunt quantitates eifdem literis denotatae , ficut in fubtraflione fimplicium, amp; ei quod rclinquitur prxfigendum eft fignum, quo major quanti-tas afficitur. Vt fi addendum fit 3^ 54 ad 2^ — za: additisnbsp;3 ^ ad 2nbsp;nbsp;nbsp;nbsp;amp; fubtraöis 2 ^ex ^ a, fumma erit 5nbsp;nbsp;nbsp;nbsp;3 Simi

liter fi lt;ï ai addatur ad — q.4, fiet fumma za^—^ d. Vbipate: fi 2 4-lt;1 addatur ad 3 /gt;¦—a, fummam fore 5 quantitates enim a 8c — lt;*, cum propter diverfa figna fint fubtrahendte, fenbsp;mutuó tollunt.

lam ad addendum quantitates diverfis literis denotatas, oportet tantum eas fuis fignis connedere. Vtad addendum a-^bzA c—d, fcribo a b cd: fiquidera quantitas c, 8c omnis alianbsp;cui nullum praeponitur fignum , intelligitur fibiprsfixum haberenbsp;fignum

Exempla additionis compojitarum.

iabc AA-


bb^A^-


lt;ib-\~ibbiabc aa-^za — 3-

fumma 2lt;«4-5 nbsp;nbsp;nbsp;5^—4^- lt;*^4- bb. \a^ZAbc. 2lt;ï(ï4-3lt;j—

J3^4-5i« lt;j4- d. zb A AAzAb ^A^—~aab aa—5 lt;ï4-6'. \ zb ZA A J^d, 3^ A AA-^ ab lA^’^-lAAb 4^4“ A6.

aggr. 5^4-3«i. ZAz^d. 5^. ^aa—^ Ab. quot;^A^ ^Ab.zAA

Add.

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8

Add.j a-\-y Summa 1 cd

Principia

2aa-\~T^ab—bb ahc a^-^2ahb-aab abc'. •^abT^aa a^'—abc a^ aab—'^abbb'.nbsp;feu aggr. «4-^ c—d.^abaabb. a* 2abc.ia^abb-\-abcb*.

E quibus manifeftum fit, ( cum ad addendum 3^ 54 ad 2 b —2lt;*,fcnbipoffit3 b lt;^a 2b — 2(J,hoceft, 5^ 34: fi-quidem 3 bamp;c z ^faciunt 5 ^, amp; 5 a — 2 lt;ifacmnt 3 a)nbsp;quantitates eifdem literis denotatas, quando diverfa habentfi-gna, fiibtrahendas efle, amp; fummseafcribendumeflefignum ma-,nbsp;joris quantitatis.

De SuhtraBiofje quantitatum com-^ofitarum',

POrrbadfubtrabendum quantitates compofitas, qua: eifdem literis funtdenotat£E , fciendumeft: fi figna eadem fuerint, 8cnbsp;quantitasèqua fubtradlio fieri debet, major fit quantitate fiibdu-cenda; turn fubtradtionem fieri ut in fimplicibus , amp;eiquodre-linquiturprïfigendum efle idem fignum. Vt fifubtrahaturlt;ï 26nbsp;ex 2lt;« j ^ : (fubtraftis^ex 2 lt;1,8lt;: 2 ^ex 5 ^,) remanet^ 3 b.nbsp;Non fecus fi fubtrahatur 3 a— 3 ^ex 5 a — 4^, reliquum ericnbsp;2 4—b.

Si verb figna eadem fuerint, amp; quantitas a qua fubtraftio fieri debet quantitate fubducenda minor fit; oportet, fubtrafla mino-rc ex majore , refiduo fignum contrariiim prseponere. Vt fi fub-trahendum fit 44- 3 ^ab 3 4 2 fubtraótis 4 ex 3 4, 8c 2 ^ exnbsp;3 refiduumerit 24—b. Similiter,fublatis4—3^ex 24—b ^nbsp;relinquitur 4 4-2

Quód fi quantitates iifdem literis defignatse, atqueadfubtra-* bendumpropofitte, diverfa figna habeantj eruntipfe addenda,nbsp;ut in fimplicibus, 8c fummseprxfigendum fignum quantitatis, anbsp;qua fubduflio fieri debet. Vt fi velimusfubtrahere4—b ex 2 4nbsp;4- ^: fubtraftis 4 ex 2 4, additisque^ad^, refiduumerit4 4- 2 b.nbsp;Eodemmodo, 244-5 «^fubduöuma 3 4—2c/,relinquet4—7 d.

Cacterüm ad fubtraliendum quantitates divcrfis literis denotatas, oportet quantitates fubducendas, variatisfignisconncöere cum üs, a quibus fubduöio fieri debet. Vt fifubtrahi debeat e—dnbsp;ab 4-3-^ ; erit differentia feu refiduum 44-^ ¦—c4-cf: variatisnbsp;nempe fignis quantitatum camp;cd.

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Matheseos Vniversalts.

Exempla fubtraBionis com^ojitarum.

Ex* 24 5;^ 54—4^-14^ 1^^ 4’—iabc-^M-h^ 244 34-9. Subtr. 4 2^. 34—3^nbsp;nbsp;nbsp;nbsp;|4^—]abc M-b^ 44 24-3.

Relicj. 4 3^ nbsp;nbsp;nbsp;24— ~b. ^ab-^\bb. |4*—{abc.nbsp;nbsp;nbsp;nbsp;44 4-d.

Ex 34 2^ nbsp;nbsp;nbsp;24-b 244- ab nbsp;nbsp;nbsp;54^ 544^-3^^ nbsp;nbsp;nbsp;24 6^quot;

Subcr. 4 3^ nbsp;nbsp;nbsp;4-3^ 44-24^ nbsp;nbsp;nbsp;24^ |44^- 4^^ nbsp;nbsp;nbsp;244'-34 9.

Refid. 24—b.a-^zb, 44 4^. 34’—{aab-\-{abb. 44 4—3.

Ex 24 ^ 34—ld «—44 343—\aah \abb-b^ 344-24 ^. Subtr. 4—bnbsp;nbsp;nbsp;nbsp;tm-T^ab-2a^ \aabnbsp;nbsp;nbsp;nbsp;44 4—^3.

DifF. a-\-ib. aquot;jd. iiab—^aa. 54^—mb \abb-h^. 244-34 9.

Ex nbsp;nbsp;nbsp;4 ^nbsp;nbsp;nbsp;nbsp;244-44 i^abc a'-'^-aab-abb-b^.

Subtr. nbsp;nbsp;nbsp;c—dnbsp;nbsp;nbsp;nbsp;44 4—6 a^-abc. aab-id^ c'^-abb.

Rel.refid.feudifif.4 ^'C a!. 44-54 5. ^al;c-agt;. ^a^-b^—

E quibus perfpicuüm fit (cum ad fiibtrabendum 4 3 ^ ex 3 4 2 ^fcribipoffit 34 2^ — 4 —'3 hoe eft,2 4—b, fubtraöisnbsp;nempc 4 ex a amp;c z bcx:} b) : quantitates eifdem literisdenota-tas, quando eademhabent figna, fed quantitates fubducenda: aliisnbsp;funtmajores, fubtrahendasefl'e, dcrclidto prsponendumelTefi-gnum contrarium.

Similiter quoniam ad fubtrahendum 4 — bcKZ a b, feribere polfum 24 ^ — 4 ^, hoc eft, 4 2 ^, ( fubtrahendo videlicetnbsp;aiza^amp;c addendo ^ ad ^) patet, qua ratione, quantitates eifdemnbsp;literisdefignatas, cumdiverfahabuerintfigna, fint addenda, amp;nbsp;fummae praefigendum fit fignum ejus, a qua fubtradio fieri debet.nbsp;Quod autem fubtrahendo 4—b cxia b^ feribendum fit 2 4 ^nbsp;'— lt;* ^,variatis nempe fignis quantitatum fubducendarum, indenbsp;manifeftum fit; quod ad fubtrahendum a qxz a b differentianbsp;denotetur per 24 ^—4, utpote fubducendo quantitatem 4, prae-penendo ei fignum ¦—, ut in fubtradione fimplicium eft didum tnbsp;at quoniam fubducendo quantitatem acxza b, plusjuftotol-litur, fiquidem non 4 abfolute tollendumproponitur, feddimi-nuta quantitated; hinc fit, ut 24 d — a minor fit quamjuftanbsp;differentia, quantitate b\ adeoque ad veram differentiam obti-l^endam, oportet addere quantitatem d, amp; feribere 24 d—4 d,,nbsp;fioc eft, 4 2 d, Et fic de aliis

^ars II. . ^ nbsp;nbsp;nbsp;Bnbsp;nbsp;nbsp;nbsp;Ds

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ÏO

PRINCIPIA

T)eMuhiplicaüone qumtttatum comfofitarum,

TJOfthxc, admultiplicandumquantitatescompofiusj Bpera-tioinftiiuipoteft ad modum Arkhmeticje vulgaris: oportet enim earumpartes mulciplicareinfeinviccm, ut in fimplicibusnbsp;eilüftenfum, atque produdla Gmul adderc. Quod autem ad fignanbsp; amp; ¦—¦ attinet iifdem prsefigenda, fciendum eft: cadem fignanbsp;(hoe eft pcr-f-,vel — per — ) facere fignum , diverfaverónbsp;(hoeeft per —, vel—per ) facere —. Vtad multipÜcan-dum a -{-b per c: multiplicatis a per e, amp;nbsp;nbsp;nbsp;nbsp;^ per -f- r,

fiunt-4-lt;ï c, amp; nbsp;nbsp;nbsp;quibusadditis, fit produéirum lt;* e -\-bc,

imac-^bc. Sic fi mtiltiplicandum fit a — ^perc, producetur a cb c.

Nee alkcr fit,fi*ad imilliplicandum proponatur is ^ per c-k-d: multiplicatis enim lt;*-4-^ per c, ut ante; amp; rurfus 4 ^ per ii! ( fi-quidem^-4- ^ non tantum per c, fed etiam per aïmultiplicari debet) :fiec ftnbsp;nbsp;nbsp;nbsp;Nonfecus ad multiplicanduin

(t—b per c—d fcribitur acad —¦ b c-\-^b d: multiplicatis nera-pc primèm ab per -f-c,fic dc—be: deinde a — ^ per — d, fit—ad ¦4quot; bd. quippe -f» a per — d, producit —ad: at—bnbsp;per—d producitjuxta regulam. Etfic dealiis. Nee re-ferc utrum a dextra an verb a finiftra initium fiat, ficut fequenti-bus exemplis manifeftum fiet.

Exempla multiplicationü compofitarum.

Malt.lt;ï-f-iamp; a—b a-^b nbsp;nbsp;nbsp;abnbsp;nbsp;nbsp;nbsp;a-^b

per c nbsp;nbsp;nbsp;cnbsp;nbsp;nbsp;nbsp;c-\-dnbsp;nbsp;nbsp;nbsp;cdnbsp;nbsp;nbsp;nbsp;a-\-b

¦J^ab^bb ¦bd aa:-\-ab

-bc

ac-

prod. ae-\-bc, accb. ac-\-bc

•^ad-Arbd

Multipl.

per


Ytö^\idi.ac-Ybc-^ad~^bd.ac- bc-ad bd.aa z ab-drbb-

¦aaah bb a bnbsp; aab-abb b^


a -f- b

ab aaquot;^abnbsp;ab-bb


aa~


lab bb a-—b


aab-{-zabb


ab-^bb aa—ab

prod. —zdb-\rbb. aa-bb. a^-'^aab-\-:^abb~lP. a^-^b^


'.aab abb ' nbsp;nbsp;nbsp;—aab abb


Muit-


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Mult.

per

ia‘^b\a^bb'

MatHESEOS VnIVERSALIS. ÏI '^dd—• eenbsp;nbsp;nbsp;nbsp;\ab—±ati

-\~^a'^b-\^ja^bb-\~^aab^ ^a-^6

^d‘^-\-lzd'’e-\‘Z^ddee — 5 ddee^de^e*nbsp;produft. $d^ 1 idfe—^de'*e\

Multipl. 44’-4*-per

24lt;ï’ 4-18lt;ilt;«—12^4-^ —204“*—Inbsp;nbsp;nbsp;nbsp;loaa— 5 lt;*

4quot;4'*^’4quot;3'*'‘—24*4''^'*‘*


produft. 44^-

Catterum advertendum hic eft, non raro utile efie, multiplica-tionem hoemodo non inftituere, (ed tantummodo eaminnuerc interferendo voculamw velM. Vtadtnultiplicandum4^^‘4'3^'*nbsp;— 244-1 per 44— 444-6’, feribo 44^ 4-34^— ^ H** ^nbsp;in 44—544.(J, vel44gt;4- 3 44 — 244- i M44 — 5 44-6.

Quod autetn 4“P^gt;^—gt; vel'—per 4-f^ciat—,{icpatct. Efto 4 — ^muhiplicandumpere, amp;fit4—bzDe: bine fiucrobiquenbsp;addatur b, fiet 4 CQ ^ e. lam quoniam xqualcs quantitates pernbsp;eaiidem quantitatem multiplicatx producunt asquales ; ideo ftnbsp;utrinquemultipliceturperr,eritaeZD b£-\-er,hoceft,auferen-doutrinquc^c,erit4r—bezo ec. Quocirca cum ftatuatur 4 — b-30 e, amp; utraque parte dufla in r, producatur 4 c—b cZDec j per-jfpicuum fit, — b dudtum in 4“ r, producerc — be.

Nec aliter oftendetur — per ¦—multiplicatum producere4quot;» Etenimfid^multiplicandumfitper r — d: ponendo, ut ante,4.— ^OQ fjcritproduftum ex4.— ^in c — d ïequale produftonbsp;ex einc — «slvele —lt;!iine:ideft,ce —o!e. Sedre, ut lupra, x-quatur4c—i^c: unde4e — bedexquabiturprodudoex 4—^nbsp;in ed. Porro cum 4—^ xqualis fit poftta ipfi e, amp; utraque parte duöa in lt;^, produ0:um4lt;i—^ jequetur produélo e: bine ftnbsp;ex4c—i’cfubtrabatur a d — bd\oco de, eisquale; eritjuxtanbsp;regulam fubtraftionis aeb ead-^bd produöum qusfitum.nbsp;E quibus liquet—b multiplicatum per — lt;5producere ^lt;3i.

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Principia

De Dïvijtone quantitatum comfojttarum.

PRjeterea, ad divideadum quantitates compofitas, operatio non abfimilis eritei, qua in Arithmctica vulgariduo integrinbsp;numeri perfe invicem dividuntur. Quod autem (igna4-!amp; —nbsp;conceniit, fciendumeft, fidividatur-4-per , aut — per—,nbsp;femper oriri ; atfi per—, vel'— per dividatur, fem-peroriri —. omninoutinmultiplicatione. Operationetn autemnbsp;live adextra fiveafiniftra incipias perinde erit. Vtad dividcn-dumrff ^cperc; divifis «i£-per (7, amp; pcr c,fiun£nbsp;utinrimplicibuseftoftenfum lt;ïamp; ^, unde quotiens qusfi-tuserit^ - -A Similiter fi dividatur 4 lt;r—perc,orietur4 —nbsp;divifisenira 4fper-4-lt;r, fit 4, amp;—per fit—b.nbsp;Non diffimili raiione dividitur acnbsp;nbsp;nbsp;nbsp;c-^bd perc iaf,

amp; fit 4 é». Cujus operatio talis eft.

j “4“ 4. “4“^^ r J ~j-c

Divid. • ac•^Ad•^bc-^-bd per c ”4”nbsp;nbsp;nbsp;nbsp;4£'-4“^^quot;4”^r-4quot;^^

o o Q o Quotiens -i-a-i-b.

Divifo a c per c, (ut in fimplicibus) fit 4, fcribendum fub lines in quotiente. hinc multiplicato diviforc c ^1 per quotientem in-ventum a, produftum ac-{-adcs dividcndo auferatur, feriben-do partes ejufdcm denominationis fub invicem, amp; reliquum fubnbsp;lineainfra dufta, Vndecum fubdu(5to4c ex4c, amp; 4ö^ex^^^^ma-neat nihil, fcribitur fub linea dufta o. Deinde divifo -\-bc pernbsp;-^.c, fit ^gt; afcribendumprioriquotienti. undemultiplicatonbsp;divifore c per hunc quotientem ^,fit prodiidum ^ c -f- ^ d.nbsp;id quod fi fcribatur, ut ante, fub dividendo, 8c fiat fabduótio j eritnbsp;pro reliquo fub linea fcribendum o. Et peraéla erit divifio.nbsp;Eodem modo ad dividendum acadbc-^-bdnbsp;perc~d;) acadbc-^bd

b

Erit quotiens nbsp;nbsp;nbsp; 4—b.nbsp;nbsp;nbsp;nbsp;-4*

Divido primum 4cperc, amp; fit 4, fcribendum fub linea in quo-* ticntc. lam multiplicato divifore c—per 4, fitprodudutn

ac-

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Matheseos Vniversalis. 13

—ady fubducendumex dividendo, amp; relinquituro. Deinde divido—^ e per c,amp; oritur — ^jfub lineafcribendum in quo-tiente. Quoniam autemmultiplicato diviforec—«(per—b, fitnbsp;produöum — bc-\-hd, amp;eoex reliquo dividendi ablato, re-manet nihil; patetdivifionem efleadfinemperdudam, amp;quo-tientem efle

Sic etiam ad dividendum nalab-^-bb nbsp;nbsp;nbsp;aa 4

per 4—b\')aAab nbsp;nbsp;nbsp;'nbsp;nbsp;nbsp;nbsp;a

o — Ab nbsp;nbsp;nbsp;—^b —b

ab^bb nbsp;nbsp;nbsp;-4“ 4

o o

fit quotiens 4—b.

Divido primüm 44per4, amp;oritur4, fcribendunafublinea in quotiente. Vnde miïltiplicato divifore 4—b per 4, amp; ablatonbsp;produólo 44—abtsi dividendo, fcribendum erit reliquum—abnbsp;iublinea dult;9:a infra — zab. Deinde divido—4^per 4,amp; fitnbsp;•—b, fcribendum fub linea in quotiente. Turn dudo diviforenbsp;a — ^ in — by fit produöum — ab^bb, quod fublatum a reliquo dividendi relinquit o. Et erit operatio finita, ac quotiensnbsp;qu«efitus4 — b.

Eademrationc fi dividendum fit 4 4—^'^per4 ^.

-ab

-ab

a

—ab

*4“ 4

Divid. nbsp;nbsp;nbsp;44—bb

Divif.4 ^) 44—bb o o

Qiiotiens

Incipiendo rurfusaprimo termino, divido 44 per 4, amp; habebitur 4, fcribendum fub linea in quotiente. Vnde multiplicato diviforenbsp;4 ^ perquotientem inventum4, producetur 44 4^, quodnbsp;lublatum ex dividendo rclinquet—4^: amp; quoniamhic terminusnbsp;prater fuperftitem — ^ ^ ad dividendum hue accelïit, ideo poft li-neameiadferibitur. Deinde divido—ab (nempe id quod modónbsp;ad dividendum acceffit) per 4, amp;habetur — b in quotientenbsp;fub linea fcribendum. Qiio fado, fi multiplicetur divifor 4 ^nbsp;per hunc quotieniem — ^,exfurget—ab — ^^ad fubtrahendumnbsp;exeo, quod rclinquitur in dividendo: quod cum poft fubtradbo-

B 3 nbsp;nbsp;nbsp;nem

-ocr page 42-

X4

Principia

nemrclinquato,quot; liquetabfolutamefTeoperationem, amp;qaotic!v tem fore 4 — h.

Necaliterferesbabetficlividaturlt;ï’ ^^per4 ^, amp; inci-piatur ab ultimo termino.


Dividend.

Divifor(« ^)

o o


'abh -4 bbnbsp;o


Quotiens nbsp;nbsp;nbsp;-t-aaab-i^bb.


Etenim divifo -4- b^ per b, fit-f-b b, fcribendum in quotiente. tumdudodivifore4 ^m ^^gt;producitur 4^^ ^* : ld

quod fi fubtrahatur ex dividendo , relinquetur — aéb. Deinde divifo — a bb per -f- ^, oritur — ah ^ fcribendum in quotiente,nbsp;quo multiplicatoper diviforem4 ^exfurgit — aab'— abb^zAnbsp;lubtrahendum ex reliquo dividendi, eritque refiduum-4-44^.nbsp;Denique divifo 44/^per4.i, prodibit '*^fcribendum innbsp;quotiente. undefimuItipliccturdivifor4 ^per 44, amp; pro-dudèum 4^ 44^ auferatur ex refiduo dividendi, eritreli-quumo. Idquodoftendit, divifo 4’ per 4 -4-^ , oriri4 4 —nbsp;ab-\-bbf quoderatfaciendum.

Sequuntur adhuc nonnulla exentplaad uberiorept exercitationem divijionis com^ojitarum.

Dividend. nbsp;nbsp;nbsp;4^—^aab-^^'^abbb^nbsp;nbsp;nbsp;nbsp;«—

DiYifor4 — b.) nbsp;nbsp;nbsp;-f- abb—¦—b\

•\-zabb o nbsp;nbsp;nbsp;quot;4- labb —‘lak-

*¦^244^-4^24^^ nbsp;nbsp;nbsp;b

•—aab nbsp;nbsp;nbsp;onbsp;nbsp;nbsp;nbsp;—aab 44.

45— aab nbsp;nbsp;nbsp;— b

o o

Qiiotiens -4-44—zab bk

Divi-


-ocr page 43-

Matheseos Vniyersalis.

-'^ddee-quot;^ddee —¦^ddeenbsp;oee

ee

Dividend. nbsp;nbsp;nbsp;^d^-{-izd^e—.^de^e‘'

lyivi{.:^dd—ee)9a(‘*-4-i nbsp;nbsp;nbsp;—^de^—

o nbsp;nbsp;nbsp;o o o

Dividend. nbsp;nbsp;nbsp;ila^h-^-^ahquot;^—

^W£\ab—'.aa)

•—o o l^^b


^a^bb

lr(Obb


¦dr\aab.


-yia

-laf^b

4

—Laa


lens

bblt;^-\~^^lt;ihb.

'—'-^AA I

D i V ld. nbsp;nbsp;nbsp;d*-b‘^ 2 lt;*.«lt;^4- 2 AAby-^AAdd-AabbV bd^

ïixw.d-^b')d'*-b'*-^zaady-\-zaetby-\-aAdd AAb^-bd^\

o o o o soo o •Quotie»s ö(*—bdd-^-bbdb^-^iAay-^AadAab.


\-aAbd Pag.j^Ot -Aabd ^'quot;•4-


bbdd\

•\-bbda


-bU\

¦b^d


d']^^- —bd ’’ —bdd. -^bbdd -\-bbd.b'^d

d\4*' ^ nbsp;nbsp;nbsp;“4quot; ^nbsp;nbsp;nbsp;nbsp;quot;4* ^

2 AAdjl\-\“ 2 AAy^ -J- AAdd -\-AAd. •—AAbd

d \ nbsp;nbsp;nbsp;-J- fl!|nbsp;nbsp;nbsp;nbsp;^ d


¦b\ mb.


”^41 nbsp;nbsp;nbsp;4

-16^'

—I Z^yy-{-^yy.

— nbsp;nbsp;nbsp;16

— nbsp;nbsp;nbsp;i6y*i iy‘f,

—*i(J I

Pag. 77.

Dividend. nbsp;nbsp;nbsp;—^quot;^Ayy—^4

Divifor^^—I (?) T*’ 8 nbsp;nbsp;nbsp;4jj—54

o——\%%jy nbsp;nbsp;nbsp;o

¦— 16y'^—1284^

o o__

Q^uottens -4“ i7‘*-4-8/j4-4*

Divi-

-ocr page 44-

ïö nbsp;nbsp;nbsp;PRINCIPIA

-^lAACcyy 4- aaccyynbsp;4- AACcyynbsp;4- aaccyy

o

Dividend.

Fag.~%. jyiy.yy-aa-cc)-^y^aay^-ccy^-iayyyr(^yy-(i^- a^cc-aac'

-A^CC o —a'^cc

o iaay‘^-ccy‘^ ayy o o- laay'^-ccy -y-a^yy

o o o nbsp;nbsp;nbsp;o

Qiiotiens nbsp;nbsp;nbsp; 7^ 1 Anyyccyy-\-A‘^-^AAcc.

-\-y'^.-^iaay‘^

•^ZAayy.—ccy‘'

IJ

77

-ccjy.

’i-Ayyj-^a‘*. -^AAccyy

771 nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp;77

-\-aace.

Pag. 5 So.D ividend. nbsp;nbsp;nbsp; \y-^y PHuy-fKuq-y.fa'^f yfiu‘*y]^fmf

Im.ï 5. Dïy.^-^-jfm pm) \y-yflt;yy-pmq-f(iuy-yPM‘^q-\-ypu^y\ jfuHij

4-f.

Quód fi quantitates dividendae occurrant, quae prajcedenti modo dividi nequeunt, fubfcribendus erit divifor ipfi^ividendo,,nbsp;interjeda lineola, llcut in fradlionibus vulgaribus. Vtaddivi-

dendumlt;i^—deperis?4-e, fcriboproquotiente^^j^^^. quo

indicaturi3^—(jedivifumeffeper^i4-e, veladhuc efledividen-dum. Sicamp; fi^^4-^«/4-ccdividaturper^ 4-ö!jfitquotiens feu

fradlio^i^t^^idf, hoceft, b nbsp;nbsp;nbsp;. Quippefaepeconducit,,

utin Arithmeticavulgari, divifionem, quantum fieri poteft, in-ftituere, amp; quod fiipereft inftar fraftionis quotienti adfcribere.. Et tantum de divifione.

De EXTRACTIO NE RADICES.

^Voniam autemde Radicis Extraclione , quae pro divifionis '^fpeciehaberipoteft,agendumreftat, fciendumeft, ejusope-rationem non efle diverfam ab illa, qua in Arithmetica vulgari ra-^nbsp;dix ex dato aliquo numero elicitur.

Etenim

-ocr page 45-

Matheseos VniVeusalts. 17 Etenim ut a mulciplicatum per a facit a a^ feu a quadratum,cu-jus radix feu latusdicimr^j fic amp; radice quadrataextraöa ex«*lt;«nbsp;provenietrurfus^. Similitercumlt;ïlt;t,hoeeft, 4quadratummul-tiplicatum per a producatlt;j’ feucubum ex 4; ita etiam extradanbsp;radicccubicaexlt;*b fieti*. Et ficdecsteris radicibus.

Nee alitcr fit fi ex quantitatibus compofiüs radix fit extrahen-da. Siciuenimex quantitatibus flraplicibus radicis extradlio non fccusfchabetatqueextraéiioradicisexaliquonumero, quxtantum unius üt charafterij: ita radix, quantitas exiftens compofita,nbsp;non aliter extrahetur, ac fi ex aliquo numero radix, quae pluribusnbsp;conftet charadleribus, eliceretur.

Vtadextrahendam radicem quadratam ex AA-^iAb-^-bb' extraho primum radicem ex aa,Sgt;c fit ^,qu£e in fe multiplicata amp; abnbsp;ablata rclinquit o. Deinde multiplicato lt;« per 2, di vido ZAb

Xi^uadratum aa-^ 1 ab -^b b aa-^i ab-^b^nbsp;onbsp;nbsp;nbsp;nbsp;00

Radix a-\-b Divifornbsp;nbsp;nbsp;nbsp;2 a

per 2 4, amp; fit ^: quod adferibo priori radici inventse a. Hinc fiducatur2 lt;ïin h,(it-^zab^ quodfublatumex 2 i*^relinquito.nbsp;Similiter fimultipliceturè in fe, fiet ^^j quaitidem ex^nbsp;ablata, reraanebit o. Et operatio eric ad finem perdudta , eritquenbsp;radix qujEfita^ ^. Etficdealiis.

Exem^la extraBïonis radïcnm ex compfith.

Quadratum — z aabb~^h^

•bb

Aa-

2 AA

Radix

Divifor

Qiudratum C^xx—iffox ioo Radix Sx — 10nbsp;Divifor 16 X

Qua-

Pars IJ. nbsp;nbsp;nbsp;C.

-ocr page 46-

i8 nbsp;nbsp;nbsp;Principia

Quadf atum a a -«I- zac -f- ccz ah— i bc b b-


it A ZAC c C Z Ab ‘ O Onbsp;nbsp;nbsp;nbsp;Onbsp;nbsp;nbsp;nbsp;O


zbc'

o


Radix A-^c—b


Primus divifor za Secundus divifor


z A-l-z c


Quadratum

Radix


per


2^4-2 £•. fecundus divifor.


a nbsp;nbsp;nbsp;lt;i

per 2 a —zab Primus divifor z anbsp;nbsp;nbsp;nbsp;a anbsp;nbsp;nbsp;nbsp;2nbsp;nbsp;nbsp;nbsp;lt;i

-i-z Ac\-i-cquotusprimus 2^ I

z a nbsp;nbsp;nbsp;cnbsp;nbsp;nbsp;nbsp;—b

4“ nbsp;nbsp;nbsp;cnbsp;nbsp;nbsp;nbsp;—b

cc.


gt;^quot. fecundus.


2 ^ —1™ 2 C

b

. 2 a b—.2 bc.


4“2.lt;2C


^bb


Cubus nbsp;nbsp;nbsp;4^^ 4.^3

4-3 aAb\-\-'b. 4quot; 3 lt;*lt;* '

Radix a-\~b Divifor 3 lt;ïlt;i

Cub. 27X®—54x5 171^?“*—i88Ar’4-2 85A:;e—i5o;v i2 5 Cub-^T^* %']x^—54^;^ gö’.v'*—¦nbsp;nbsp;nbsp;nbsp;8x^4- 60XX—15; 0x4-12 5 Rad. 3 xx_

o nbsp;nbsp;nbsp;o4-i3 5x‘‘—i8ox^4-i2 5xxnbsp;nbsp;nbsp;nbsp;Q o 3XX

-t-i3^x''—180X34-225XX nbsp;nbsp;nbsp;3XX

9 o nbsp;nbsp;nbsp;onbsp;nbsp;nbsp;nbsp;9x^.

Radix nbsp;nbsp;nbsp;3xx^—^ax-i-^.nbsp;nbsp;nbsp;nbsp;per 3

Primus divif. 27 xquot;* nbsp;nbsp;nbsp;—-54x^

Secundus divifor 27x'f—36'x5-f-i2xx •^z'ix*

27X'* i.div.

-2xquot. primus.

.2 X

-ocr page 47-

Matheseos Vniversalis. 19

— 2 a:

.— 2 a:

27 ATquot;*

'z x

— 2 AT

-— Z X

-y 4.VAr

4-4.V.V

—54a''

^xx

-2 At

1ZX*

—8a-3

per ?

~6x^ ^xx -6 x^

^¦^(Sx‘*. ' nbsp;nbsp;nbsp;^']x‘'3(JA-^ i2^^.Secand.div’.

^-Jx^

5 nbsp;nbsp;nbsp; 5

5 quotus fecund. f nbsp;nbsp;nbsp;^

zj

3 XX— 2 X ^

Z7Ar^—-^Cx^ ïixx 4-75XX—50A: Hhii5-

_ nbsp;nbsp;nbsp;4-___5 nbsp;nbsp;nbsp;^___

i:}'^x*—iSox^ 6oxx. nbsp;nbsp;nbsp;¦ -zz'^xx—i'^ox.

Cxterutn fi quantitates, exquibusradix extcahidebet, taks fucrint, ut radix prjedilt;9:o modo invenirinon poffit, delignabitutnbsp;ipfaprxfigendoquantitatibus propofitis fignum'y/. Vtadextra-hcndum radketn quadratam cna fcribo y' ^; quo indicatucnbsp;radiccm quadratam ex 4 lt;7 eik extraftam, vel adhuc eflc extra-hendam. Sic amp;nbsp;nbsp;nbsp;nbsp;dcfignabit radicem quadratam ex

aa-^hb.

Similiter ad extrabendum radicem cubicam ex aaq^ fcribo Y C.a.aq. Vtamp;y^ C. agt; •h' oFbl ad extrabendam radicemnbsp;cubicam ex 4’ — b^-^-abb. Quae quidem radices vocantur quantitates Surds feu Irrationales, admodum numerorum furdorumnbsp;feu irrationalium, dequibus Aritbmeticiagunt.

Vbi notandum, fignum |/, vocariSignum Radicale, atque In geilere ufurpari ad denotandam quamcunque radicem, five Quadratam , five Cubicam, five QuadratO'quadratam,amp;c; fed ad il-lam diftinguendam, communiter fcribi Y Qjt etiam fimplici-ter ad denotandam radicem Quadratam; amp; y^ C, ad denotandam radicem Cubicam: amp; Ynbsp;nbsp;nbsp;nbsp;V gt; denotandam ra

dicem Quadrato-quadratam, amp;c. qus radices etiamfic defignan-

tur;-j/@,y0,y0^g^c; atque ab alüs, hoe qu oque pado;

3(3i,amp;c.

DE

-ocr page 48-

-ao

Principta

Tgt;E log 1ST IC a fractionvm.

Vandoquidem cx divifione quantkatum fimpliciumSi: com-pofitarum ollenfumeftoririFracliones, ficut in Arithmeti-caviilgari, quarum operatio eafdena leges fequkuratquenume-rorum fradorumvulgarium; fatis erit, ii luppofitis horum regu-lis, illarum operationem exemplis exponamus.

Hinc, cumper fradionem quamlibet defignetur femper divi-fionem aliquam cfl'e faciendam, iitpote illarum quantitaturaquat numeratoris vicem gerunt, per quantitates, quse pro denomina-tore habentur, facile conftat, li numerator denominatori fue-ritsequalis, tune per fradionem illam defignari unitatem. Vt

fï ’ ^1 ^’ amp;fimiles. Vndepatet, quanam ratione unitas dc-

notari poflit in formam fradionis,cujus denominator fit is, qui rcquirltur.

QnödfiYci-aa^,aa-~l’i’, amp;c. in formam fradionis defignare

Yctimus, opor.tettantum,afliimptoamp;(«lt;*¦—I'é’, amp;c. tanquam numeratore fradionis, fubfcribere pro denominatore unitatem,

hoe pado: nbsp;nbsp;nbsp;^, amp;c.

Porró fi quantitas aliqua , ut 4 , defignanda fit in formam fradionis, cujusdenominator eafit, quaepr3efcribitur,ut(!/,autnbsp;amp;c;oportetmultiplicat04per^ ,autperlt;i ^, fcriberenbsp;adnbsp;nbsp;nbsp;nbsp;aa~\~ah a

7 ’ nbsp;nbsp;nbsp;-a b

Non aliterfit, filt;i fit redigendura ad formam unius fradionis. Etenim, multip]icatolt;«per denominatorem^i, addatur produdo^ïnumeratoramp; (amm^ad-^aaiab^chbatur denominator d, habebiturquenbsp;nbsp;nbsp;nbsp;. Sic amp;, —^4 in formam

-ad


Haud fecus fi 4


unius fradionis redudum, facit ‘—, - .

* nbsp;nbsp;nbsp;d

reducatur ad fradionem, fiet-j.

Caeterura notandum bic, cumad dividendum a a per ^^,fcrlba-tur^^pro quotiente; ideo adhunc quotientem five fradionem

raultiplicandum per diyiforem feu denominatorem égt;lgt;, pro

pro-


laa


-ocr page 49-

Matheseos Vniversalis. ¦ m

produÖo fcribendum effc numeratorem aa. Nonfccusfi multiplicctur pefis—produftumerit ^Vndepatetadmui-tiplicandum per iah‘, quoniatnmultiplicato per z b,pro-

duÖum eft a; fupereft tantum ut hoe produdum adhuc multipli-cetur per a, uthabeatur qushtum produftuuii^. Similiterad multiplicandum iper zah: cum multiplicato iper 2, fiat i; hincnbsp;mukiplicandum tantum reftat i per^^, amp;fitprodu61;umqu2efi-tum I « ^ feu Etficdealiis.

¦Dé’ ReduBkne fraBionum ad pmflkiorss.

J Am ad reducendum fradlionem nbsp;nbsp;nbsp;ad fimplicioremjelisa com-

‘*4 • Sic amp; ad abbreviandum --£j nbsp;nbsp;nbsp;abc

numeratoris atque denominatoris » hoe eft , divifio tam lt;* quam

niuniliterac-, quse tam innumeratore quam in denominator

reperiturjfiet . Sic amp; ad abbreviandum : elifis literis 4,

abc per ab, fiet ~

Eodem. modo. ad abbreviandum nbsp;nbsp;nbsp;quot; • quoniam divifo

44£¦ peroritur, idquodmultiplicatumper cd dd,pro~

ad minores terrainos reda-

hh

eacaa J

cddd

ducit44c—a ad; hinc

n nbsp;nbsp;nbsp;. aa

ctum , ent ~ .

a

Pari ratione ad reducendum nbsp;nbsp;nbsp;; quia ( ut

fupra)divifo4lt;ïlt;'peroritur id quod multiplicatumper

cd — nbsp;nbsp;nbsp;producit4 4C'—aad; amp; rurfus — bbc divifo per cd,

bh nbsp;nbsp;nbsp;^

oritur— quod per nbsp;nbsp;nbsp;multiplicatum producic —bbc

J^bbd; hinc ~~abbreviatum,facit nbsp;nbsp;nbsp;.

c d-dd nbsp;nbsp;nbsp;lt;J

„ai ccoomm-^Aa‘cc m^ptf ¦ nbsp;nbsp;nbsp;r •nbsp;nbsp;nbsp;nbsp;cc mm

oofpz* ^mpi z* nbsp;nbsp;nbsp;' ppz‘*

a.ac—a adacd acfd nbsp;nbsp;nbsp;, ,nbsp;nbsp;nbsp;nbsp;, aa

Non iccus-ciI.Yd_-rcducitur ad nbsp;nbsp;nbsp;^ vei

Sicamp;-abbreviatum, tacit

/» n ft f» r* -1. 4 w h? -y* nbsp;nbsp;nbsp;*

//».! 5..

-ocr page 50-

Principia

^ Nam aacaadi'mhm^ercddd, facit ; $c acd-^adddmCam^ct: c ddd,^tcit—lt;*.

Similiterfifaerit -f TaJ'^b ' nbsp;nbsp;nbsp;'=*'*

2 ah-\-hl?, 5c relinquiiurpoft divifionem ^ ^^^ a i-Xnul-la hïc quoüentis aib habita ratione) . Deindedivido44

1 a b-\-b b per reliquum 4-1 ^ é z amp; fit quotiens ~

Hinc cumpcraöa fitdivifio, amp; nihil remaneat, dividenduserit nuraerator—ab b Sc denominator 4lt;* z a b-^b ^per labb

z^’, Invcnieturque nbsp;nbsp;nbsp;, pro numeratore,

amp; nbsp;nbsp;nbsp;, pro denominatore.

hoe eft, multiplicando ubique per z b è,habebimr nbsp;nbsp;nbsp;•

lt;13 _£5

d ci-^h y

Divifis enim o' —

Nee aliter fit ad abbreviandum

per 4 —bb, relinquitur a b P: dein a abb^ziAbb — é’, fitqaotiens^~ p amp;perada eft divifio abfque reliquo. Qixa-re fidividatur 4^ — b^ Sc a abb^cïabb —nbsp;nbsp;nbsp;nbsp;,

fiet ^ I, pro numeratore.

amp; nbsp;nbsp;nbsp;_p. i , pro denominatore.,

Ideoque fi ubique multiplicetur per b b, fiet fractio reduda

A d d h h h

d 1,

... nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;1nbsp;nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;—aah^dbh_6? nbsp;nbsp;nbsp;•-

d^^dh

Etficde aliis.

Sïtïiili operationc rcducitur nbsp;nbsp;nbsp;' ^ ----—• VC

ad

3c4-5

Oftensa igitur ratione, quafraöiones adfimpliciores reduci poflunt, fupereft ut expUcemus, quo paddo datis duabus aut pln-ribus quamitatibus, five fimplicibiis,live compofitis, inveniaturnbsp;minima quanticas, qus per ipfas fine reliquo dividi poteft. idnbsp;quod in fequentibus ufumhabere patebit. Eftautemoperatiofi-milis ei, quafecLindumprop. lib. 7. Elemcntorum Euclidis,nbsp;datis duobus numeris, minimus invenitur numerus, qui per ipfosnbsp;fine reliquo dividitijr.

-ocr page 51-

Matheseos Vniversalis. x3 Vt, ad inveniendum minimam quantiutem, qux dividi poteftnbsp;per duas datas aac Be cd;conftitutis aac amp; cd in formam fraétionis,

hoe paélo: nbsp;nbsp;nbsp;reduco fradionem hanc ad cjus primitiyam, feu

(Impliciorem^-j.Quibus juxta fe poficisjhoc modo:

11 multiplicatio inftituatur per crueem , procreabitiir eadem quantitas ex aac md, atque ex cd \aaa'. hetenim utrobiquenbsp;aacd, minimaquippe quantitas, qujEllnc reliquo dividi poteftnbsp;fcvaacamp;c cd.

Sic amp; ad inveniendam minimam qiiantitatcm, qus dividi poteft nbsp;nbsp;nbsp;aac^aadSc cdddi reduco(utante) tra-

ö.ioncm nbsp;nbsp;nbsp;ad ejus primitiyam : Turn multiplicato

ancaad^cï d,n\t c d—d d per a nbsp;nbsp;nbsp;quantitas quïfita a a cd

'ei^dd. minimafcilicet, quxdivifibilis eftper aacaadSc cddd.

Similiterfidentura*—h‘' Scaa a nbsp;nbsp;nbsp;quoniam

• nbsp;nbsp;nbsp;t ¦¦¦ dnbsp;nbsp;nbsp;nbsp;ènbsp;nbsp;nbsp;nbsp;1?“^nbsp;nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;lt; • f ¦nbsp;nbsp;nbsp;nbsp;f

citur ad-^--— ^ nbsp;nbsp;nbsp;miutiplicamm per a ra-

cit lt;*5ab‘'; erit ^5'—quantitas qusefita.

Eadem ratione fi datte fuerint — 25x6ta:a:-J-iox-4-25,, crit quatfita quantitas 5nbsp;nbsp;nbsp;nbsp;—2^ xx— 125 x. Et lie de

Cïtcris.

Quód fi verb compertum fit aiit conftet, duas illas datas quantitates ad fimpliciores reduci non pofte, fed primitivas efle; opor-tetunamper alteram multiplicare, ad inveniendam quantitatem quxfitam. Vt ad inveniendam minimam quantitatem, qus divi-

adfimplicio-

fl4 - h*

di poteft per a aabSca-^è‘. quoniam ïes terminos reduci nequit,multiplico 4^ — ^ per ^, ( cum

fecundumprscedentiafcribendumforet

amp; fit qusfita quantitas a^abb.

Catterüm datis tribus aut pluribus quantitatibus, invenietur minima quantitas qu$ per ipfas abfque reliquo dividi poteft, hoenbsp;modo; Vt ad inveniendam minimam quantitatem, quaedividinbsp;poteft peri*^—abb,aa-{-'i-ab-\-bbyBi aabb: quaero pri-mum, ut ante, minimam quantitatem, quae dividi poteft per

-ocr page 52-

^4 nbsp;nbsp;nbsp;Principia

^5a bh amp; a a 2 ab-\-bb, amp; fit nbsp;nbsp;nbsp;-\-a} b^AabbAb^.

qu2ecumamp;dividaturper^i*—bb, manifeftumeft af^-\-a^baabb'—cfTe quantitatem quatfitam. Sic amp; fi datx fiierintnbsp;^ ^ d|d h ^nbsp;nbsp;nbsp;nbsp;' '!d y amp; a-\-b ; inventa primum minima

quantiiaccij’-—^j^^qatedividi poteit per duas —b^Si aa-^abt fucante),quoniamipfa dividi nequit per tertiam 4“ ^: hincnbsp;' ’’’ab*amp;c 4‘*-4-4p fimilitcr aliam quaEro,ut4^ — b

a}b* 44^^'— ab^. quae cum lire etiam divifibilis fit per


ad 4 o' bb


jreliquam a-\-b, patet o' — 4^^ ^ 4^ ^ ^ nbsp;nbsp;nbsp;b'^A a b’' ¦

efie quantitatem quaelitam. Et lie de catteris.

De ReduBione fraBionum ad emdem demminationem.


b^


Vibuscxplicatis, facile*eftoftendcre, quaratione fradtioncs diverfe denominationis reducantur ad fradiones ejufdem

denominatiönis. Vtadreducendumfradiones nbsp;nbsp;nbsp;can

dem denominationem : qusro primum minimam quantitatem, quicdividi poteft per denominatores4 aeSe cd (utjam eft often-fum), amp; fit 4 4C4!: quse erit denominator communis. lamadin-venieadumnumerator.es, dividatur denominator inventus aA£dnbsp;pev aacSeed, unumquemquefcilicetexdenominatoribusdatis,nbsp;amp; quotientis d Sc a a multiplicentur pernumeratores b^dScA^nbsp;datarum frafl;ionum,ut habeantur numeratores qutefiti b^dd Sc A^y

fiuntquefradtiones quxfitte ^

Similiter ad reducendum

nominationem: inventodenominatore communi 4^ c d—aaddy minima nempe quantitate, qusedividipoteft per aac—AAdScnbsp;cddd, divide 44 cöl — aaddpamp;ï aac'—a ad Sc cddd ,Scnbsp;quotientes dScaa mültiplico per numeratores b''ScA^ ^’jfiunt-

£ d nbsp;nbsp;nbsp;„ a' a a


_ amp; __

aacd aacd

-——1 amp; nbsp;nbsp;nbsp;adeandem de-

aac—aad cd—da


quefraélionesqusefitcE--

* nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;aacc

Eodem modo fi — Sc


-aadd

X •


aacd ^-^aadd


- -— reducantur ad ean-


dem denominationem, provenient

Xi ~—¦ 30 3CX-t- 115 X

5X3.-l^XX-113 X


15X xx iox-)-z5

115 x-|- 615


Sc


-i5xx—IZ5X

Non



-ocr page 53-

Non fecus


Matheseos Vniversalis.

lt;i3—a ah quot; b

__ Acr — nbsp;nbsp;nbsp;__

a h


^ aaJ^ab^

€tx fubeodem denominatore, facient --d’ nbsp;nbsp;nbsp;hh


iy

aa-^ ab~^»hh j


-a6* ’

—5 a.iy -J-aa amp;*


~ b H' b b ¦ -• b^ U il b^

~ ^ nbsp;nbsp;nbsp;5 i ^nbsp;nbsp;nbsp;nbsp;5

a®-agt;b-^alt;bb-a^h^-\-aiiblt; -aè’ nbsp;nbsp;nbsp;’

- a^ h~\- bblt;-a^ nbsp;nbsp;nbsp;—— a3 Z»' a ah'’-a


a'-a‘b-\-iiibh-ai fct-|-aaZ)gt; -aè*'

a* — a? 6 -t- 1 a® b fc-i a' b? -4- j a» b‘^ — i a’l h’ a a b'’


ySC


-a b'


a'


a^ b a^ b b~~ ~a^ bquot;^ a a b’ ¦


¦ ab*


Additione ^ SuhtraBione fraElionum.

A Dditio amp; Subtraftiofradionumeodem modoperficiuntur, ¦^^atcjue additio amp; fubtra^io numeroriun fraótorum vu]ga-rium. Etenim fi fradiones ejiifdem fuerint denominationis,opor-tct tantum earum numeratores addere aut fubtrabere, amp; fumtnsnbsp;vel reliquo fubfcnbere denominatorem communem. Vt ad ad


dendum '


.bb


fummaerit


a H’^b b


Sic amp;


2 ad


additum ad


d-\~


facit-

bb


, feu 2 Non fecus fi addantur-j-^ ^


dc/


eritfumma


zbd-\-hb


b d^'''quot;’ b-f-rf nbsp;nbsp;nbsp;‘‘¦T- ”b d^

Quodfi fradtiones diverfe denominationis fuerint, rediicends eruntpriusadeandemdenominationem; quo fado, operandum

eritutjamdidumeft. Vt ad addendum—diL ad


-V


fictfumma y —toxx-4-2to% bx5


5X XX-4-IOX 25 ’


x -J- 5 XI — 2 5 X %¦

Non fecus fi addantur **


-I2-5X ai —a ah


eritfummadd^


a*b‘^ ^ a nbsp;nbsp;nbsp;^ a^h ^

6a^hquot;^lt;)a'’ bb_lt;)a^ h^^ja^.h*— 6^?ib^'^^aah‘^—xaégt;7-4-^*


4!.


a? —4^ nbsp;nbsp;nbsp;hbb^ -^aab^ab^

lam adfubtrahendum df de nbsp;nbsp;nbsp;, fcribo pro differentia'

d nbsp;nbsp;nbsp;. lad

- , reliquum ent —j-

hd * nbsp;nbsp;nbsp;bd ..nbsp;nbsp;nbsp;nbsp;. dd~^hb


Eodem modo fubdudiis f— a t

d-—e d.

1 a Similiter


Nec aliter fit, fi fubtrabendum fit

11. nbsp;nbsp;nbsp;D


b4


b d I de


bb-


¦feu


aad cd—dd


Ete-


nitn


-ocr page 54-

Principia


nimreduSis ad eundem denominatorem, fiauferatur


de ¦


A’ -4quot;


¦aadd


relinquetur


aah^ d


xJ


ex


aacd — aadd

xi — 5 oxx'


.X5X xx4-iox4-i5


, remanebit


Sic amp; fi tollatur


3c4 4- 5X5 .— 2.5XX-I15X


Eadetn ratione ad fubduccndum


-ah


de lt;»,rcduda quanti


tate ^ ad denominatorem i? ^, demptoque-


-ab , aa-^ah -r de -—tt- 1


fiet reliquum nbsp;nbsp;nbsp;• Non fecus fi fubtrahatur ^ -1- de lt;1 ^ ^

relinqueturlt;»— nbsp;nbsp;nbsp;.

De Adulti^licatione fraBionum.

A D multiplicandum per , multiplico numeratorcm a h

per numeratorcm de, ut amp; denominatorem c per denominatorem ƒ (ad modum fradionum vulgarium), fitque produdum

aide o aahh nbsp;nbsp;nbsp;, . .•nbsp;nbsp;nbsp;nbsp;tab , . la) hlab^

cc-— multiplicatum per nbsp;nbsp;nbsp;producit nbsp;nbsp;nbsp;nbsp;'

Ad faciliorem autem operationem non rarbconvenitabbre-viare quantitates percrucem. Vt ad multiplicandum a anbsp;nbsp;nbsp;nbsp;hh ch h dnbsp;nbsp;nbsp;nbsp;—eihhnbsp;nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;j f i

-a^ rab bl-= q^om^maac-aad-igt;igt;c

¦Jy-hbdamp;c cd—^(lt;aireducuntur adfimpliciores^lt;ï— bb8cd,\itamp;C abbèc aa’\‘Zab-\‘bbz.Aa a—a bamp;ca-^b', hinc loco multiplicand! aac‘dad—b b c bbd per —(«^^multiplico aa—bbnbsp;perlt;ïlt;?'—ab', amp; loco multiplicandi aa ^ ab-^-bb’^cï cd—dd


multiplico 4-1-^ per d: eritque produdum Porrbad multiplicandum 44—bb'^^x —


a^ b'aabb-^ abi ad-\-bd


¦ab


a-\-b


: fubftituto I


pro denominatore ipfius a abb, quoniam numerator a abb amp; denominator a b reduci pofluntad^—bamp;c i, hincmulti-plicatis numeratoribus interfe, utamp; denominatoribus,fietpro-


dudum


«3 .


¦ 1 a ab- - abb


feu4^ — 2 aab abb.


Eadem ratione cum multiplicatur a nbsp;nbsp;nbsp;per4—2 b y gt;

quoniam a alab b^


d h-^h h nbsp;nbsp;nbsp;a alO-h-^hh

eft, -T—r- nbsp;nbsp;nbsp;^-


-ocr page 55-

Matheseos Vniversalis. 2.7

i aah zahb lgt;3

—^reducipofl'untadlt;* — bamp;c i jhinc multiplicatis4 4—ab

feu

-f.^^per4 — hySca^zY i .ptovenit

a a — 2 ab ibb— —

Similiter fi ad multiplicandum proponatur ^

reduclis xx—gt; 5 xamp;— 5 amp; i,itcmquexAr—•! 5amp;^ 5 5 8c I,mukiplico tantum x — 5 perjc — 5»^^^produ-10 x4-


KX XX-1C


r.x-


ad X öumarAT


Ptïterea ad multiplicandum lt;? y — ^:quoniam4

per4 — ^facit44—a ^,8c nbsp;nbsp;nbsp;per4 — ^facité^; hincprodu-

öiim qutefitumerit 44—ab bh. Qiia quoque ratione multi-


- 2 aab ab b. -ah

plicabitur -jpp per44'—hbydc producetur^’

multiplica-

cumenim44—é éfiatex4H-^in4 — nbsp;nbsp;nbsp;— - . ,

tumper4 ^producat4 4 — a,b, fupereft tantum multiplican-dum44 — ab per4—uthabeatur4’ — z aab abb.

Denique fi multiplicandum fit “jj per c—d, fiet, divifis cddd^ttcd, produ61:umnbsp;nbsp;nbsp;nbsp;•

De Di'vijtone fraBionum.

J^Ddividendum^ per : omifib coramuni denominatorc £',divido4p per^lgt;, fietque quotiens ab. Pari ratione finbsp;¦^rf-dividatur pernbsp;nbsp;nbsp;nbsp;, onetur

4a

Quód fi denominatores fuerint diverfi, redudio adeandem denominationcm fiet, fi multiplicatio inftituatur per crucem, ut

invulgaribus.Vtaddividendum nbsp;nbsp;nbsp;—fnbsp;nbsp;nbsp;nbsp;, quo-

niam multiplicato prioris numeratore 4^ ¦—¦ b^ per pofterioris de-nominatoremc, amp; hujus numeratore 44 — ab bb perillius denominatorem A fiunt a’ c*—c amp; 4^ nbsp;nbsp;nbsp;nbsp;; hinc quotiens

«ü:

ai cbi c

D J, nbsp;nbsp;nbsp;Ad-

-ocr page 56-

a8 nbsp;nbsp;nbsp;P R I N C I p I A

Adyertendum autemhiceft, ad facilitatem operationis , fra-élionum numeracores, ficut etiam denominatorcs non raróad

fimpliciorester.ninosrcducipofl'e. Vtaddividendum ~~ab\-Ui

per nbsp;nbsp;nbsp;cum numeratores a*amp;c aa ab reduci poffint

ad— aah al^b8c a,di denominatorcs— lab bb öca — ^adlt;j—b amp;c i; ideo loco multiplicandilt;»‘*—^quot;^per^?—b^nbsp;multiplico — aa b abbb^ per i, amp; Rta^aab a b bb^;nbsp;amp; loco multiplicandi aa ab perlt;j^ —’lab b b multipliconbsp;a^cta'b, amp; Rtaaab. unde quotiens divilionis fit

«3-aab-^-abh-b^ , nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;~nbsp;nbsp;nbsp;nbsp;%¦gt;-

-—--7-- vel a —. Eadem ranone li — --^—

a a —a o nbsp;nbsp;nbsp;quot;anbsp;nbsp;nbsp;nbsp;x x—— i o x-f- z 5.

dividaturper nbsp;nbsp;nbsp;orictur’^^~'^’‘^'^^^^~— . Nama;^ ¦—6zlt;

X—5 » ^ nbsp;nbsp;nbsp;XX—5Xnbsp;nbsp;nbsp;nbsp;)

amp; XX ^ a; reduci poflunt adx’—5 xx 25. x— 12 5 amp; Ar,quin amp; XX-—' iOAr 25nbsp;nbsp;nbsp;nbsp;x-—’5 ad AT—'5amp;; i,unde produóta ex

niultiplicatione per crucem fiunt x^-^^xx-^zlt;^x-—'lajS: a; — ^ a;.

Ponó ad dividendum —iaab-\-abh per—: fubftituto i

prodenominatoredividendi^^—zaab-{-abb, quoniamnumeratores — z aab-^abb 8gt;c aa—4^reducipofiimtadiï—bSc i ; hinc multiplicatis^ — ^perlt;«4-^amp; i per i,fietquotiens^lt;j—bb.

Sic amp; ad dividendum Aa

ai-\-^aab-^-t, abh a-^b nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;,,

-: divido4’ 4lt;ï(JP4-3(jamp;^per44-^,

amp; fitlt;2lt;j 3^^,undequotiensquxfitusfit nbsp;nbsp;nbsp;Haudaliter,

a a-.—a b nbsp;nbsp;nbsp;¦nbsp;nbsp;nbsp;nbsp;. / t’ ^nbsp;nbsp;nbsp;nbsp;^ x

, onetur ^ Et nbsp;nbsp;nbsp;' ~ per

ah

, nbsp;nbsp;nbsp;, onetur

a-{-b nbsp;nbsp;nbsp;’


fi dividatur^^'—lt;ï^per xx '^ X, orietur


a-^- b . Ac —aai


Acr


aa-


X—5

aa ab. Etdenique ^ perarq-5 , exfurget


5 X nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;^ 'nbsp;nbsp;nbsp;nbsp;o X—5

De Radicum extraBione exfraBionihus. '

Vm in Radicum extraéiione ex fraftionibus radix ex nume-ratore amp; denominatorc extradta exhibeat radicem quatfi-


tam: hinc fi extrahenda fit radix quadrata ex


aahh


quoniam ra-dix



-ocr page 57-

MaTHESEOS VnIVERS ALIS, dixquadrata-ex44^'^eft/i égt;,8c radix quadracaex tceftc, fcribo

pto radice quaefita

Eodera modo, fi extrahatur radix quadrata ex

aa-hb

¦ nbsp;nbsp;nbsp;- Pariratione ad extrahendam radicem quadratamex

j_64xx.—Igox

: quontam 4

’ nbsp;nbsp;nbsp;anbsp;nbsp;nbsp;nbsp;aa-i-^ab ^l,!,^

64 XX itfOX . nbsp;nbsp;nbsp;r.

-in rormam rra-

^5

öionis facit nbsp;nbsp;nbsp;^ quadrata ex 100—160 x

¦8x

8x

feu

Non fecus radix cubica ex

ö'4JrA;cftio — 8x, amp; radix quadrata ex a 5 eft 5 j erit radix

quïfita quot;quot;

^7x«—54x54.^ylx4_Ig8x^ x8 5xx—150x4-115,

'ent

5XX-

X»-

-9XX4-17X—17 nbsp;nbsp;nbsp;X }

Quod fi quxdta radix praidido modo ex numeratore atquc denominatore extrahi nequic, prxponiturdatcE fraótioni fignumnbsp;radicale V-Vt ad extrahendam radicem quadratam ex —ac^

fcribo-y/ nbsp;nbsp;nbsp;velquia — lt;1 £¦ in formam fraftionis

. ccxx-^abbc o ,

'» amp; ex denominatore 4 ^^extrahi poteftra-dix , qua;clt 2 h: ideo quxfita radix fic quoque fcribi poterit

^-. Similiter radix quadrata ex erit-----.

Tj ^ j ....... M-ybb yaaybb

dem de reliquis radicibus eft intelligendum.

logistic A QVANTITATVM SVSIDARFM.

^^Vemadmodum fraéiiones oriuntur ex divifione imperfeéla quantitatum, quarumuna per alteram fine reliquodividine-quit. ex extraöioneradicis quantitatum radicem non haben-tmmex utgunt quantitates Surdaj, quarum operationem fequen-tibus exemplis cxponere vifum fuit.

T)e ReduB^ïone cj^uantitMum fitrdaYutn.

^Cicndumitaque, quod, ficutadoperationeSifraaionumdi-vcrfe denominaiionis oportet priüs ipfas ad eundem denomi-

D 3 nbsp;nbsp;nbsp;nato-

-ocr page 58-

30 nbsp;nbsp;nbsp;Principia

natorem reducere, ita amp; opus fit, quantitates furdas, fi diverfa fi-gna radicalia habuerint,reducere ad idem fignum radicale. Quod fit, fi adnumeros, a quibus radices denominantur, minimus in-veniaturnumerus, quiperipfosfine reliquodividipoffit. Vt adnbsp;reducendum Ylt;* ffieu ynbsp;nbsp;nbsp;nbsp;Sc Y|/0 ^ lt;2 .j' ad idem

fignum radicale: quaero ad 2 amp; 3 (numeros a quibus YY^ denominantur) minimum numerum, qui per ipfos line reliquonbsp;dividi poteft, qui eft 6. lam cum 6 divifo per 2 oriatur 3 , amp; pernbsp;3 divifo oriatur 2 j hinc aq multiplicandum erit infecubicè, Scnbsp;aaq quadratèjfientque fub eodem figno Ynbsp;nbsp;nbsp;nbsp;Y ®

SiY nbsp;nbsp;nbsp;q qïcwY® q q.Sïc Sc Y

eodem figno radicalierunty' Y(tabbScY Y ^‘‘b abK

Hue refer cum quantitas aliqua rationalis per multiplicatio-* nem in fe reducitur a^ aliquod fignum radicale. Exempli gratia:nbsp;ad reducendum 1* ^ ad idem fignum radicis cum Y aa bbnbsp;oportet multiplicare4 ^infequadratè,amp;; fitnbsp;nbsp;nbsp;nbsp;z ab-^-bb,

Non fecus fi multiplicetur ^ in fe cubicè, fiet

¦j/C.lt;ï5 344^ 3lt;i^^ /'*fub eodem figno cum y'C.a^b^ abb.

Etficdealiis. nbsp;nbsp;nbsp;•

Deinde fciendum, quantitates furdas non raro ad fimpliciores reduci pofle, -tollendo ex figno radicaliquiequid eft rationale:nbsp;nimirum, dividendo quantitates fub eodem figno Y comprehen-fas per aliquod Quadratum,vel Cubum,amp;c. per quod multiplica-tionc fuerintproducftge.Vt 3/75 -^reduci poteft ad 5 lt;*-1/3 : namnbsp;75 4^producitur ex multiplicatione 25 4lt;jper 3 , quarum radices funt ^ a ScY 3 i adeout, fiy^ lt;2lt;ïdividatur perquadratutnnbsp;2^ aa, fub figno radicali tantum feribendum fit 3 , hoe modo:nbsp;lt;^(iY 3. Idquodmonftrat 5 hoceft, y 25; multiplicatumnbsp;efiepery' 3.

Eodem modo cum a^b-\-aabb dividi poflKtper quadratutn aa, amp;oriatur ab-\~bb-, fit utpro Y b-{-aa.bb fcribiqueatnbsp;(lY cl b-\-bb.

Similiter quoniam ti' baabb-^iaabc-\-abccbbeezb^ c-^b* dividi poteft per quadratum aa-^z ac-^nbsp;cclab—2^c4^^,cu;us radix eft lt;i cquotiens eftlt;?^ ^^i

hinc

-ocr page 59-

MaTHESEO S VnI VERSALIS. nbsp;nbsp;nbsp;3I

hinc loco nbsp;nbsp;nbsp;—aabb-^-iaabc-^-abcc-

fcribi poteft a-^cb -j/^ b-^-bb.

^aawgt;

fcribi poterit-^ Yoo ^mp:

aaoomm

Nonfccuspro-j/-^^-,— ..........y

redudo enim ultimo termino ad eandem denominationem cum priori, poteft utriufque numerator dividi per a amm,c\i\\is radixnbsp;cft Am, oriturque 00 4mp. Denominator auterti cum fit ratio-nalis, liberabitur a figno -|/, extrahendo radicem G'amp;ppz.z..

Eadem ratione loco

y C. nbsp;nbsp;nbsp;—^x^-\~i'jx'^-—15 — io8 XX 324 a:—324

icribipoteftAT — 3-j/ C. at’ iz. Etficdealiis.

Verum enimveró quoniam fspenumero difficile eftinvenire Quadratum, Cubum, amp;c. per quod divifio, ad hanc reduétionemnbsp;necelTaria, inftituipoflit; non inutile fuerit, fi hoe loco oftenda-nius, qua ratione datarum quarumlibet quantitatum diviforesnbsp;omnes inveniantiir, perindeatquein numeris eftoftenfum. videnbsp;p. 300.nbsp;nbsp;nbsp;nbsp;_nbsp;nbsp;nbsp;nbsp;...

Dividantur data: quantitates per quantitatemaliquam primiti- 'Ratiom-vam (hoceft, quxnon nili per unitatem autfe ipfam dividi po-teft ), amp; rurfus quotiens per hanc eandem five aliam primitivam, idque fiat donee perveniatur ad quantitatem aliquam primitivam, quarum-quse per fe ipfam eft dividenda. Vt ad inveniendum diviforesnbsp;omnes quantitatis^H -^-aabb: divido^i^ ba a b b ^cr a,8cnbsp;aab-\-ab b, id quod rurfus per a divifum dat ab-^bb. lam quianbsp;quotiens hicper 4ampliusdividinequit, divide4pernbsp;amp;provenit a-yb, quecquantkas eft primitiva, ideoque per fenbsp;ipfam dividenda. Quibus peradis relerventur divifores a,(i,bynbsp;a-yb.

^ b nbsp;nbsp;nbsp;bh

^ h ^ b b

ab~\^bb

a

a

b

d’^b


lam ut ex hifce diviforibus inveniantur divifores omnes quanti-tatis4’ ^“tquot;^lt;ï^^,multiplicoprimumlt;aper^, amp;fitiï^. Deinde ^per i,a,Scaa, fiuntque b,ab,8i lt;r;lt;^^.Deniquemultiplico4 ^nbsp;per i,a,aa,bya b, Si a ab, amp; dam a-y b, a a a b, o' -J^aabynbsp;Abb by AH b“fquot; Ab bfSc b-4*AAbb-

-ocr page 60-

RINC IPIA

a.

a a.

h.

aégt;- a a b.

Atcjue ita divilores omnes erunt i ,a,aa, b,ab,aab, a-^b, aa-^ab, AAb,a,b-^bb, aababb, amp; b-^a abb.

Sic amp; ad invcaiendum omnes divifores quanticatis^*'—¦% a'^ bb ^zaab^ b^: divido— i aquot;'bbi aab'^ perquanti-tatem primitivam aa-{-bb, amp; fit lt;»¦*— 3nbsp;nbsp;nbsp;nbsp; id quod

rurfus divilumper quantitatemprimitivam aa-^-ab—bb dat aa—abbb, quaequantitas etiam primitivaeft, adeoque pernbsp;fe ipfam dividenda. Eruntque divifores refervandi aa bbynbsp; a bb b,amp;c a aa bb b.

-ah—bb -ab—bb

ta-

aa-

~zaab‘^-\-b^Y‘'—'h ‘*‘^bb-{-b‘'

aa..^~bl^ aa^^ab—bo Ex quibus ut inveniantur divifores omnes quantitatis-*®—2 a!^ bbnbsp;¦—’Z aab'^-^-b^: multiplico primum aa-^bb^exaa-\~abbb,nbsp;amp; fit a‘^a^ bab^—Deinde i,aa-^bb, aa-^abbb,nbsp;amp; a^-^ a^ b-\-ab^nbsp;nbsp;nbsp;nbsp;a aababbb, fiuntque^lt;j—abbb,

a‘^-—• a^ b'ab^'b^, a^— ^aabb-^bquot;^, Sc a^ •— 2 a'^bb—¦ 2aab‘'-^-b^.

, nbsp;nbsp;nbsp;I-

OA'^^bb. nbsp;nbsp;nbsp;aa-.^^Abbb.

A‘‘-\-a'^b-{-ab^b'^.

aa—ab— bb. a‘^a^b—ab^--b*.a*— 3aabb b‘*.A^— za'bb—taab''' b^. Ita ut divifores omnesfint i,aa-\- b b,aa-\~ abbb, aquot;'-\-a^ bnbsp;-j- a b^b^, a aab—b b,a‘^a^ bab^b'^,a'^— ^ aab b^bquot;*.nbsp;Sc a^2 a^bb2 aab*- -^b^.

P^g-7^,

lin.ii.

Eodem modo ut inveniantur divifores dmnes quantitatis a^ 2 a'*cc aac*: divido a^-f-ia^'cc -f-aac* per lt;«, amp; fitnbsp;a^ -i-2 a^c c d c^qiiod rurfus per a divifum, dat a‘*-^zaaoc- -c‘*.nbsp;lam cum hie quotiens dividi amplius non poffit perlt;! autefimi-Icmvequantitatem, divido a''-l-zaacc-i-c'*peraa-f-cc,vel,nbsp;quod hic idem eft, ex a‘*-^-2aacc-t-c^ extrahoradicemqua-

dratam

-ocr page 61-

Matheseos Vniversalis. 33

dratamlt;ilt;ï-l-CÉ-, quadenuopcrfeipfamdivisa, provcnitr.Vn-decumdiviforesrekrvati fint a,a,aa-{~cc,di aa-^cc; ïieo ut ex lis inveniantur diviforcs omnes quantitatislt;*® z a^c c-^aac*:nbsp;multiplico pritnum per a, amp;fit ^ deinde I , a, 8c aa pernbsp;aa-\-cCi üaat({i\t aa-\^ c c, a c c y Sc ^ a a c c: acdeni-({ue a a ~j~ c -i-a c c, amp; a'^-^aafcpevaa-j-cc, amp; fiunt4'' nbsp;2aacc-i-(;\a^ 2 cc-t-^ic\ amp; lt;*^ ^ c-^aac‘‘ ,• erunt-que divilores omnes \ya.yAa,aa,-\-cCyA'^-\‘^cCyafgt;-\-Acicc ^

^ nbsp;nbsp;nbsp;2 AAC C -J- o'nbsp;nbsp;nbsp;nbsp;2 A^ C C -J* Ac'^y8iA^ -{- 2 A^^ C C —J- A A c'*.

“* ~^'^‘^*''^~^I^AC‘'\a'-\‘2A^CC-\-AC'^ j lt;I^-\‘2AACC-\^C'^

^1 nbsp;nbsp;nbsp;a\,nbsp;nbsp;nbsp;nbsp;aA-\~CC

I.

a a.

cc. A^ acc. A‘' A ACC.

-CC. a'^-\-zaacc-\-c‘^. a''-\-ia''cc-^ac'^. a^-\-2aquot;'cc-^aac‘^.

aa-


Similiter ad inveniendum divifores omnes quantiiads bAAbb-\-2 aah c-\;-Ab c cAh^ bb cc2 b^c-\-b‘*’. quia, la-6ta divifione per by oritur — alt;»é 2 aa c-\-acc^Abb-\-b CC'2 b bc-\-b^ y 8c hu jus quotientis per a b, oritur lt;« lt;3'—nbsp;2Ab-\- 1 AC'—'2 bc-\-cc~^bb,8c radix quadrataex a alab

2 AC--2 b C “h cc-\-bbt^ta-J^cby\xoczïk,AA'—2 Ab

2 AC2bc-\-cc-\-bb divilumper4 e'—b, dat A-^C-b-y

divido demum a-\-C'—^^perrf C'— nbsp;nbsp;nbsp;amp; fit i. Vndecum di-

vdores refer vati fint^, lt;?- ¦/', c—by8cA-{-C'b-, multiplico b per lt;j-f- !gt;, amp; fitlt;ï^ turn lybyA^bySiAb.-^-bb per c— iquot;,fiuntqueI* c—b,Ab-\-bcbbyAA 4- a c -j- b cnbsp;- b b,8i AA bnbsp;nbsp;nbsp;nbsp;Abc -\-bb cb^: ac denique «i-j- cby a f-

hc'h by aa-\~ac -gt;rbcbby 8i AAh-^Abc-\-bbc'—^^per A-{-cby fiuntquelt;ïlt;«—^ 2 4Ó zac2 b ccc-\-bb,Aab-\-

2 Ab c-^bc czabb'2 b b c-{-b^, nbsp;nbsp;nbsp; 2 a ac A C C-A A b

•— ab b-\-b c c—2 b b c-\~b'lt;,8c nbsp;nbsp;nbsp;b-\-A Ab b-\-2 AAb c~^A bcc

Ab'^ -\-bbcc—-2b^ c-\-h‘^. Atque ita divifores omnes erunt i, bya-{-b,Ab-^bb,a-i-cb, Ab-\-bc'bb^AA-^A c-\-bcnbsp;'—b byAAb -\-Abc-\-bbcb^yAa2ab-^2Aczbc-^-cc

bbyAA h 4quot; 2. Ah C’^b c c'Zabb'2 b b c-\-b^yA^ -^2 aac Ars II.nbsp;nbsp;nbsp;nbsp;Enbsp;nbsp;nbsp;nbsp; rfcc

-ocr page 62-

34 nbsp;nbsp;nbsp;P R I N C I P I A

• -acc'iitaêgt;—ab b-^b c c—i bhc-k-b^-,^ a^bciabb-^-iaabc

• -abcc-ab^-^bbcc—zé’c équot;*.

Non fecus fi proponatur^’ hcab'^ c, invenientur ex divifo-ribus refervatis 4, b, c.,a—• b, Sc a-\- bèWiiorcs feqHentes: i,a, by a b, c,a c,b c, a b c^ab^a a¦— a b,a b —¦ b b,aaba b bya c b Cynbsp;(tacahc,abC'bbc,aabc—a bbCya-\-b,aa ab, ab b bynbsp;aab-{-abb,a c-\-bc,aac-\-abc, abc bbc, aabc-\-abbcynbsp;aa‘bbyO^ •— abb,aabb^ ,a^ bab'^yaacbb c,a^ c—ynbsp;abb c, a abc.'—Cyèc a^ b cab^ c.

Neque praetereundum hoe loco videtiir, quopaöo horumdi-viforum ope du» plurefve quantitates datasalia ratione, quam ex fuperioribns facile fuit colligere, ad firapliciffimos terminosnbsp;reduciqueant. Vtadreducenduna^ï^'—abb^aab —nbsp;aababb—^b^ ad terminos finapliciffimos, eandem cumipfixnbsp;rationem habentes ; quaero primo ( ut ante ) omnes cujufquenbsp;quanticatis dacae divifores : eruntque ipdus —a b b divifores i,nbsp;a,ab,aaab, a,-\~byaa-^abyaabbySc a,^abb: ipfiusnbsp;autena aab — P divifores erunt 1, by ab, ab'bb, a-\-bynbsp;a bnbsp;nbsp;nbsp;nbsp;b b,a abb,Sgt;c aabb^: at verb ipfius aab—abb

b^ divifores erunt i,lt;ï—•bya-\-b,aabb,aa-\-iab-{-b by èca}^aababbb^. lamcuminter ipfostres fint, quilibinbsp;invicem refpondeant ,ut —bya-\- b,amp;i aabh, quorum openbsp;datse quantitates ad firapliciores reduci poffunt ; hinc ad inveniendum terminos fimpliciffimos.divido a^abbyaab,aab—amp;nbsp;a^ aab—abbb^'^eraa —nbsp;nbsp;nbsp;nbsp;(utpote diviforem pluribus

dimenfionibus conftantcm),fiuntque nbsp;nbsp;nbsp;Vbinotan-

dum, quantitates propofitas fore inter fe primas , finullicx divi-foribus libi mntuó refpondeant.

Qus ratio inveniendt divifores non ineptè quoqtte adhiberi poteft ad fraöionum abbreviationem. Vt ad abbreviandum

rdefu^a. ^ Tab b 1' nbsp;nbsp;nbsp;numerator quam denominator dividt

poteft per a-i-b, potent pro nbsp;nbsp;nbsp;fcribinbsp;nbsp;nbsp;nbsp;. Et fic

de exteris.

Inventis autem omnibus diviforibus, videndum eft numaliqui ex ipfis fint quadrati, velcubi, amp;G., qui fireperiantur, adhiberinbsp;potenint ad prxdiftum moduraliberandi quantitates ex figno radical!.

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MaTHESEOS VnIVE RSALIS. 35 dicali. Vtquiainterdmiores quantitatis a'b-^-aabh reperiturnbsp;lt;juadratum «lt;*, poterit -y/ a'b-k-a ab b, dividendo per a a , reducinbsp;zday' ab b b.

Sic amp; cum baabb i aab c abccab* hbcc—-zb^ c b'^ pro diviforc habeatquoque quadratum Aa-^z ac-^ zab—zb c-\-bb, poterit pro

cc

a'' baabb-^- z aab c-^rA b c c

fcühïa TZZly]

ab^ -{-b bcc — z b'' cAr b'^

_bb. Similiter cum numerus 7 5 inter di-

viforesguoquehabeat quadratum numerum25, reducipoteric

quot;Y']') aazA'^ ay Ita amp;,quia 1200 dividi poteft per numeros quadratos4, is^ z^ , 100, amp;400; poterit pro 3/ izoo aa bbnbsp;lcribi2 4^|/^Qo vd^aby vel ^ aby 48, vel 104^3/12,

veldeniquc2o4^y'3.

Quod fi inter divifores pratter unitatem quadratum nullum autcubus amp;c. reperiatur, non poterit data quantitasprscedentinbsp;modo reduci, niliveliseam infbrmamfraftionis defignare. Vtnbsp;quia 10 praeter unitatem quadratum nullum inter divifores ad-mittit, poterit 3/104 a., dividendo 10 per aliquod quadratum,nbsp;utlubet, ut4,25 , loo, amp;c. denotarihoc paéto: 243/1, velnbsp;5 43/f, vel 1043/^, amp;;c.

Sciendum denique, quod, licèt ha:quantitates omnesperfc confideratx furdïe exiftaht, tarnen inter fc collate duorumfintnbsp;generum: aliac enim diciintur Commenfurabiles feu Communi-cantes; alise verb Incommenfurabiles feu non Communicantes.

Communicantes funt, qus affinitatem habentcs cumquanti-tatibus rationalibus, aut etiam numeris, inter fe funt ut quantiias rationalis ad quantitatem raüonalem, feuficut numerus ad nu-merum.

Non Communicantes verb funt, quarum unius ad alteram rc-lationon eft ut quantitatis rationalis ad quantitatem rationalem, aut numeri adnumerum.

Ratio autem dignofcendi communicantes a non communican-tibuseft, fi, pottquamadfimpliciffimos terminosfuntredudse, reperiantur inter fe efle ut quantitas rationalis ad quantitatem ra-tionalem,aut numerus ad numerum.Vt 3/ 75448.: yzyaafiintnbsp;communicantes, quia divifione per 3/ 3 , maximum earwm com-

E z nbsp;nbsp;nbsp;ma-

-ocr page 64-

Principia

munem diviforettijredLicuntur ady 2^^ aaamp;Y9 ««lt;*,hoc eft, ad

5 nbsp;nbsp;nbsp;3 4; adeout pro-y^ 75nbsp;nbsp;nbsp;nbsp;amp; -y^ 17^4 Icribt poffit 5 lt;«)/ 3

6 nbsp;nbsp;nbsp;3 («-j/ 3, qu2E inter Ie flint ut 5 lt;2 ad 3 4, vel 3 ad 3.nbsp;Eodemmodo communicantes erunt-y/-y/mbb-\-h*^

quia utraque divisa per aa,-irb ^,oriuntiir -y/amp; -y/y ^,fcu 4 amp; ideoque reducunturad»? quot;y/ aa-^bo amp; ^ 3/^ -f-^quse inter fenbsp;funtut(«ad^.nbsp;nbsp;nbsp;nbsp;_

Similiter communicantes funtl/-J- nbsp;nbsp;nbsp;amp;

r ^ tl •

a ao 0 mm . A.a a mi • nbsp;nbsp;nbsp;j ^nbsp;nbsp;nbsp;nbsp;/'-i nbsp;nbsp;nbsp;o.

-—--^ : quippe reducunturad ^ y (? 0 4 öC

K yam

y

y/ o ö 4 mp, quarum unius ad alteram ratio eft,ut ^ ad — , feUj» ad

Haud aliter communicantes erimti/.v‘* öar* 2 ia;-v 7 2 ar ioS

-120 .r 300: redudlsenimad ar 3 y xx^ 12 amp; 5 —AT y/ ar ar 4- 12, habent inter fe earn rationem,

amp; y/xquot;*—^10 x54-3 7 X X-

qas eft ipftus ar 3 ad 5 — x. Et fic de aliis.

De AMtüone amp; SuhtraBione quantkatum furdarum.

Ad addendum vel fubtralicndum quantitates furdas, oportet primüm explorare utrum fint communicantes nee ne ; finbsp;enim communicantes fuerint, adduntur tantum vel fubtrahunturnbsp;quantitates velnumeri,quiextra fignum radicale reperiuntur. Vtnbsp;ad addendum y/ aa Scy/ z'] aa , hoe eft,54y/'3amp;3lt;?y/ 3,nbsp;fcribo, additis 5 amp; 3 pro fumma 8lt;«'y/3;amp;2«y/3, pro ea-

rundemdifferentia, utpote fubl.itis 3 4 ex j ___

¦ hb- Similiquot;

Eodem modofifuerint y/ a‘^ aab b êi yaabb b‘',hoe eft, ay aa bbamp;b y/ Ta Tb • addendo amp; fiibtrahendo^ amp; b, eritnbsp;fammza by tn* ¦\-bb,ic differentiae:—by

fKK

lt;er ö p„pona.ur yi?;

'.yooJ^ji^mp amp; — y/oo qtwp, erit fumma£55i^ yoo-^-^mp^

amp;dif-

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amp; differentia


MaTHESEOS VkI VE R S ALl S. 37 Y 0 0 ^mp, Nec aliierfitfihabcatur


Zaa m


V-

vel

bb nbsp;nbsp;nbsp;• b

ata-: eritenim

lin.lZ.

Y b bXX amp; Y bgt;b-

funama —'j//'^^—Y^ bb xx. Pari

rationeadditis'l/ at'* é’ a i -v a-{- 72 x-\- to8 amp;_

Y — IQ :^7 XX — izo a; 300, hoc eft, ar -{- 3 Yxx izSc JZITxYVj^ 12,eritrumi-n3 8|/ A-Ar 12, eif-demque fubtraöis, erit differentia 2 x.— iY •*¦ a 12..

Quod fi vero non communicantesfuerint, non poteruntaddi velfubtrahiitautunam radicem conftituant, quocircaaddendacnbsp;vel fubtrahendx fuht mediantibus fignis amp; —. unde Btnomianbsp;amp;Miiltinomia exfurgunt.Vt (i addendum UtV aa-^bb3.AYbb^nbsp;feribo profumma Y^^•\-bb-\’Y^é jamp; adfubtrahendumnbsp;1/4(j—b b de Y^‘^^bbt feribo pro reliquo Ya^ bb—Ynbsp;Non fecus fi addatur a-^ b 3.d Ynbsp;nbsp;nbsp;nbsp; b b, erit fumma

a~h b-i-Y aa -\r b b \ at fi fubducatur Y a a,b h do. a -j- b, erit reliquum (i-\~bY aA~\~b b. Cum enim^s ^fit quantitas rationale, amp;lY^ '*-f-^^quantitasfurda,non magiscomipunicantesnbsp;effepoffunt, quamomnes quantitatesfurdae, quse diverfisfignisnbsp;radicalibus defignantujr. Haud diffimili ratione concludes lum-mamt'gt;^aa-\'bb-^AYaa-\-bbamp;iaab bbY^^ bbeffenbsp;144 ^—bYaa bb, amp; differentiameffc zbb’Y‘^~YbyaA-^bb.

De i^Multiflicatione quantitatum fitrdarum.

quantitates dat3eluntcommunicantes,oportet, multiplica-tis quantitatibus vel numeris extra fignum radicale pofuis,

produftum multiplicare perquancitatem velnumerumfubfigno

radicalt contentum, ut habeatur produdlum quxfitum. Vt ad niultiplicandum YTÏ lt;»4 per-j/ 27 44,hoc eft,5 ^Y3 3 3»nbsp;multiplico primum 5 a per 34, amp; fit 1544: turn 15 44 per 3,

critqueprodudtumqi’£Efitum45 44. nbsp;nbsp;nbsp;__

Eodemmodoad gt;^n1tiplicandumy a aa b b^er YAahb b*, boc eft:, aY44 É'^’per^y44 ^^: mukiplicato 4per^ , amp;

£ 3 nbsp;nbsp;nbsp;p’^o:

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38 nbsp;nbsp;nbsp;Principia

prodult;?rO(ï^perlt;?4-j-fiet: produdum qu^fitum et^b ab^. Nee alitcr fït li ad multiplicandum proponaturnbsp;y x^-{.6 x’a I a; .V 7 2 A' 108 pernbsp;y.x^—iox’-j-37xA;— 120 A 3 00,hoc eft,x 3|/.VX I2,nbsp;per 5 —xYXX 12 : Multiplicatisenimx 3 per 5—^x, fitnbsp;15 2 X—XX,quodmultiplicatu!nperxx 12 ,produótumnbsp;facit 180 24X 3 XX 2 X^-x'*.

Qiiod fi datx quantitates nonfuerintcommunicantes, opor-tet tantum multiplicare quantitates fubfignis radicalibus com-prehenfas, amp; produdo prtefigere commune fignum radicale. Si verb fignaradicalia diverfafuerint, reducenda prins funt ad idemnbsp;fignum, ficutfuperiüs eft oftenfum, amp; deinde operandum, ut jamnbsp;diöumeft. Vt,admultiplicandumperquot;i/ Cis(: multiplicatisnbsp;ab'^zïcd, prsfigatur produólo ah cd fignumnbsp;nbsp;nbsp;nbsp;fit produftum

qusefitum Y i^bcd. Sic amp; ad multiplicandum Y bh per Yaa—b tgt;-. multiplicatis^lt;ï ^^perlt;«,«—bb, fiet produólumnbsp;Y«*'*¦—Similiterfimultiplicaridebeat YdA-^bb^zxa-^bynbsp;rcduco prius ^nbsp;nbsp;nbsp;nbsp;^ ad idem fignum radicale, amp; fit YAa^\¦^ab^\¦hb\

turnmultiplicatis nbsp;nbsp;nbsp;ah-^bb'^zxaa-\-bb, fitprodu(5i:um

Ya^-\-z a} b-^^x aabh-Af-z ab^ -if-bquot;quot;vel etiamferibendohoe pado: a b Yaa-\^bb. Nee aliter fit fi multiplicandum fitnbsp;a~\-Y ^cperlt;i y^ ^£',hoc eG:,a-j-Y ^cin fe : multiplicopri-mum a-^Ybc,^zra,8c fitlt;t^ lt;ï|/^c: turnper Y^^ynbsp;fitque 4|/bc-\-h c.quae produéta fi addantur,fiet produdum qusc'-fitumaa-^hc-\-z aYbc. Nonfecus fi multiplicandum propo-natur y aa,-\-bb-if- Ya a—b ^ per a-^b b—Yaa—: quianbsp;multiplicando Yaa-\-bb pery'aa-^bb.,ècnbsp;nbsp;nbsp;nbsp;—^^pcr

— Yaabb (omilfisfcilicet tantum fignisradicalibus) fiunt aa-\~hbSiaa-\-bh', at verb multiplicando 4/ aa-^bb pernbsp;—Y a abb)amp;cY aa-^bb per-|-j/ a a—^^produdaeva’*nbsp;nefeunt: hinc produdum quasfi turn zntibb.

De Divijtotie quantitatumfurdarum.

iO I datae quantitates funt communicantes, oportet tantum divi-*-'dcrc quantitates , velnumeros , extra fignum,radicale pofitos,

amp; quod


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aa

pcry 27^4,hoeeft, 5 nbsp;nbsp;nbsp;3 per 3 lt;1V 3 : divido 5 ^per 3 feu

5 per 3 ; eritque quotiens qu£ffitusfeu if- Sicamp; ad dividendum

Y^ aM per nbsp;nbsp;nbsp;^ YaY Jlgt; per igt; Yaa-{-tgt;h:

divifis (jper Btquotiens ^ . Nonfecus y lïi’eefeu ey di-

vifumpery date. Etficdealiis.

Qudd fi communicantes nonfueriiu, dividends crunt quantitates fub fignis radicalibus comprehenfs , amp; ei quod oritur prsfigendum eft commune fignum radicale. Vt ad dividendumnbsp;y a* ba b'‘ per y aa^b b: divifis a} b(ib^ per nabb ^ fitnbsp;lt;* b; unde quotiens qusfitus erit Y ^b.

Etquidem fi Imnaradicalia fuerintdiverfa, reducendaprius crunt ad idem fignum, amp; deinde operatio inftituenda erit, ut jamnbsp;diftumeft. Vt ad dividendumnbsp;nbsp;nbsp;nbsp;per y -\~aab b'vavA-^

tiplicando4’-f- a b b 'xnïcyiix. i a‘^ igt; b a a b‘'guare divisa y A^'-^ia-^b b-^-aab'^ per y^i-* .«iTJ,erit quotiens Y(ta~{-bb.nbsp;Sicamp; fi dividarury z aquot;’ b — 2 a b^ — ^‘*per^ ^: multi-

Matheseos Vniversalts. 39 amp; quod oritur erit quotien? qu^fitus. Vt ad dividendum Y7 5

~b*

plico primum a -y b iufe, vn fiat fub eodemfigno radicali y aa-\- 2 ab-\-bb.^c\^\o faö;o,fidividatury—xa^b-per y aa-\~x ab-\- b b, fiet quotiens qusfitus y a abb.

Non alia rationc nbsp;nbsp;nbsp;divifum per yaa-^-bb-^ivLcit y aa-Ybb.

quippe divifo quadrato per fuum latus , oritur latus. Vnde fi -4-^^^dividaturpery lt;«4 ^^,orietjjr^y 4^-)-Porró fi dividendum fit 4^ -Yabh^ab Y^t^ bh per aYaa-\~hbynbsp;divido primumnbsp;nbsp;nbsp;nbsp;h b per4 y44 ^nbsp;nbsp;nbsp;nbsp;fit,ut ante, y44 ^i^j

^'^^noYYAa bbper 4y aa bb,8i fit ^,unde quotiens qnsfitus erit Y^‘^ bb b.'i^oa fecus fi dividatury'lt;2‘'-H24’^—24^*—44 ^i5nbsp;per 4-4- ^jOrietur Ybb4 b. Similiter fi dividendum pro-ponatur ab-\- bY bc per 4 y ^ c •. quoniam 4 b divisa per 4, ea-dem exoritur quantitas ^,qus provenit dividendo bY bc per y hc\

hinc quotiens quxfitus erit h. Eodem modo nbsp;nbsp;nbsp;—hbc—4^ ^

igt; Jgt; c

y bc divifumper4 — Y nbsp;nbsp;nbsp;facit4^— ~V~ ¦

Pofteaad dividendum 44 — ^cper4 y be divido 44 per 4,

amp; fit

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40 nbsp;nbsp;nbsp;Principia

amp; fit lt;ï,quod multiplicatum per |/ é^rproducit^'y/ ^ f,eritquere-liquum dividend! — «y' bc‘bc. divifojam — ^fperlt;«,fic y , quodmultiplicatumper facit—bc: hocigiturfinbsp;auferatur a rcliquodividendi — bc, relinqueturo , amp; abfolutanbsp;crit divifio, eritquequotiens quatfitus^ — y bc. Eodemmodonbsp;abcd diviiam per yab—yc dydityab-\-ycd: amp;c a^ bcybcnbsp;divifiimper4 '^ b c,ddXAA-\-bcay b C'. ^ aab bccddnbsp;divifumperquot;^ aby c d, dit a b cdy ab a b cdy cd: 8cnbsp;a} b—divifum perlt;iiï4-lt;«y^ bc, dit ab—by ut amp; 4-abc aa — ^cy^ ^cdivilum perlt;»—y b c,dit a a-^b c-\-z aybc.

Denique ad dividendum y 4-per c¦—d: quia^/ a^-^-b* pcrc — dCm ycc—2cdi4-4lt;idividinequit, fcriboproquoticnte

yclY¦^ nbsp;nbsp;nbsp;, veletiam hoe paflo:nbsp;nbsp;nbsp;nbsp;l/a‘* b‘^.

tientem —:8iaa yabcd pcr^4-y'^c,facit

Yaa—bb nbsp;nbsp;nbsp;ïnbsp;nbsp;nbsp;nbsp;gt; a^ybe

Sic etiam ad dividendum 1804-24 x-Y-t, xx -{-ix'^^x'* per 8 y a; A-4-12,fcribitiir proquotiente

Eodem modo fi dividatur a •/lt;2^*4-^ ^ per 4- fict quotiens y aa bb. Similiter«lt;i4-^i’divifumper y^lt;?4—/’exhibetquo-

ad-\-y'ahccl

I 8o4-14!i4- nbsp;nbsp;nbsp;-3C4

syxx ii

qiüa 180 4- 24x4-3 xx z x’—x‘‘produciturcx i 5 -3-2 x—xx inxx i2, quadratum nempeipfiusy xx-4-12, fitutferibinbsp;^ 15 4- i X'—X X inx x-f- 12.nbsp;nbsp;nbsp;nbsp;,, .V I lt; 4- 2 X — XX

8 yxx-3-i2

quoque point--y__:==-- , vclbrevius

yxx-3- 12, utpotedividendo xx4-i2per y xx4-i2. Non aiitcr fi 180 -4-24 x 3 XX 2 x^ —x‘* fit dividendum per

- -^- _ nbsp;nbsp;nbsp;I 8o4*i4x4-’1xx4-2x3—x

X 4- 3 yx X -3-12 , Icribo pro quotiencc —— nbsp;nbsp;nbsp;^—-

X4-3 y XX4-12

^ nbsp;nbsp;nbsp;60--¦TIX4-3XX-Xi nbsp;nbsp;nbsp;n .

feu-,---^ nbsp;nbsp;nbsp;. nam iöo 24x-t-2xx 2x’—x^

yxx-3-ii nbsp;nbsp;nbsp;¦nbsp;nbsp;nbsp;nbsp;1 I a I

dividipoteftperx-|-3,amp;fit6’o — i2X 5 OC ' oc ^ vclquo-

niam60— I2X 5 xx^—x^produciturex 5-2-xinxx i2,fir

-xin X X 4- 12


ut etiam fcribi poffit


5'


feu 5 —xyxx-3- i:


¦y X X -3- 11


De

-ocr page 69-

41

Matheseos Vnivers alis.

De ExtraBioneRadicis G^adrat^ exBinomiis.

Modus j quo ex quantitatibus biuomus radix quadrata ex-trahttur, non differt ab eo, qui in numeris adhiberifolet ad inventionem radicis quadrata: ex Binoniiis, clique tails:nbsp;nbsp;nbsp;nbsp;exirahcitdi

^ nbsp;nbsp;nbsp;¦nbsp;nbsp;nbsp;nbsp;r J ¦

SftbdfiElis ^aadratis farÜHW- dati Binomii a fi mvicem, ji radix quadrata reltqui adpartem majorem addatur, ?£ ab eadem aufera- tamexBi-tur ; emnt radices qmdraU ex [emtjfe fumma amp; differentie, per ft-gnum vel-— dats Binomii connexa-, btnapartes radicis qmfita.

Vt ad extrahendum radiccm quadratam exaa-\rbc % aff b Cy fubtraho i^aahc,quadratum minoris partis ex a'* zaab c b bcenbsp;quadrato partismajoris,amp; relinquitur^'*-—z aabc bbc r, cujusnbsp;radix quadrata ^—^caddita admajorcm partem4 amp;nbsp;ab eademablata facitfummam 2 lt;*lt;«, amp; differentiam zbc, qua-rum fjmiflesfunt^/ï amp; bc ; unde radicesquadratsfunt^ amp; ffbcynbsp;quaeficonnciSantur per fignum-|-,eritradixquxfitaa-^-ff bc.

Sic radix quadrata ex nbsp;nbsp;nbsp; a; «zerit ¦y'£,

Eodetn modo fi extrabenda fit radix quadrata ex a bffab-\-zab\ fubdutSo qzïzi é^,quadrato partis minoris,ex adb-Sfi aab b-^a b^,nbsp;quadrato majoris partis, eritrcliqui agt; bz aabb ah^t^èlvc.nbsp;quadrata,*—bff ab. qu3E fi addatur amp; auferatur ex majori partenbsp;a-\- by ahy^tt fumma zaff ab,amp;i difterentia zbff a b, unde fe-miffium radices qiiadratse conftituunt radicem qusefitam.

y ay ab-\-y hy Ab{^\xyy h-k-y y ay^.

Nccaliterfiicum extrahitur radix quadrata ex a d y.bc-{-

1 y abcd: eteniinfubtra(5lo44^clt;^,quadratominorispartis,cx aabc-\rzabcd-,\-bcdd,siM2idva.to majoris partis,relinquetur aabc

2 4c ^ 4-cujus radix quadrata eftzï — dy bc'. hscergo fi addatur amp; fubtrahatu r ex majori parte zi-H 4 •y/ bc, crit fummanbsp;z ay bc, amp; differentia z dy bci Rx quarum dimidiis fi radicesnbsp;quadrats extrahantur,fiet radix qusfitay/zjy/ïc-J-y'dy/ bc welnbsp;y y aabec^y y ddb c.

Bars II. nbsp;nbsp;nbsp;Fnbsp;nbsp;nbsp;nbsp;Qubd

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41 nbsp;nbsp;nbsp;PRINCIPIA

Quod fi, fiibduciis quadratis partium-dati binomnafe invi-cetn, reliqui radix quadrata amp; major pars binomii communican-tes non fuerint: fatiuserit ipfi binomio fignum univerfale radi-cis quadratas prsfigere. Vtadextrahendam radicem quadratam

Pag. 6. ex — nbsp;nbsp;nbsp; ifï^ ^^fcribo-p^—aquxradi

ces vulgó appellantur Vniverfales.

©£ T^EDrCTIONE ^QVATIONFM.

(^Voniam ad refolvendum aliquod Problema, idipfum fup-^ponendum eft ut jam fadum , atque nomina imponenda funtquantitatibus tumdatis, turn qusefitis; amp; quidem pro datisnbsp;a D. Des-Cartes ordinariè ponuntur priores literas Alphabetinbsp;ayb^c^ècc. proqu3efitisautempofteriores;c,,j,ar,amp;c ifitutper-currendo Problematis difficultatem, eo ordine, quo omnium na-turalifïimè pater, qua rationediólae quantitates, nullointerco-gnitas amp; incognitas fado difcrimine, afeinvicem depen(ient,nbsp;tandem invcniacur via quantitatem aliquam duobus modis expri-mendi. idquod JEquatio vocatur. Vndecumasquatio nihil aliudnbsp;fit, quam mutua comparatio duarum rerum jequalium, quse variènbsp;d.enominantur: facile conftat, quantitates hafce cognitas amp; incognitas, proutdiverfimodefuntaffeds atque difpoiitae, diver-fasefficerepoflej£quationum formulas, quse tarnen per fequen-tes regulas reduci queunt ad hafce fimilefve fpecies:

z.ZDb, aut Z.Z.ZD

z? ZD az.z.-\-bbz. — c’,aut

¦\-bbz.z. — nbsp;nbsp;nbsp;, amp;c.

Dlt;? ReduBione per Additionem.

^^Tfihabeaturtequatiointern:, —3 amp; 12, hoe eft, fi fuerit ^ z. — 3 CD 12: quoniam fisqualibus acqualia vel idem addas,nbsp;ea quae fiunt funt sequalia; hinc fi utrinque addatur -f- 3 , fietnbsp;4 CO ï 5. nam —¦ 3 amp; 3 addita faciunt o.

Sic amp; fi fuerit;?:—b 00 o, addendo utrinque b, fietx. zob- Aut

fiba-

-ocr page 71-

Matheseos Vniversal IS. 43

fi habeatur b—zZOo, fiet,addendo utrobique z:., ^ CO c- Et fi ha-beaiurcz,—00o,ent?. t GO aq: \xtSgt;c dk? — lt;z«i^aequetur o, fictz,* 00 aaqy amp;c.

Nonfecusiihabeatur —nzjbbz.z.ZDd'^ — c’ z:,adden-do utrique parti-\-b b z.z-,fietzf‘ZD‘^zJ-\^bbz.z.—c’ z. d\

Exqiiibusconftat, quantitates figno¦—^adkdas addi utrique parti, li eximantur ab una parte, amp; in alteram partem iransfe-rantur fub figno -j-.

De ReduBionefer SuhtraBionem.

'P\Eindefifueritz,4-3 00 la; q,uia{iabatqualibussqualiavel idem auferas, illa quat relinquuntur iuntsequalia, fit ut, fiib-trahendo utrinquc 3, habeatur s, 00 9-

Eodem modo fi habeatur z.?. lt;it00H, fubtrado utrinque lt;«c,fietz:z;, X — az. bb.

Similiter z.^ ic^ ZDn z.z.-¥bbz,-¥c^ rcducetur ad nbsp;nbsp;nbsp;^ s. c

•\-bbz. — c’, fubtrahendo utrinque z cK

Vnde colligitur quantitates figno adfeöas ab utraque parte fubtrahi, eximendo ipfas ex una parte amp; transferendo in alteramnbsp;partem fub fignoatqueadeó quicquidvel additione vel fub-trailione transfertur, adfici figno contrario.

De ReduBione jper Adultiplicationem,

^ Orrófiad reducendumproponatur 5 : quoniam atqua-

lia per jequalia vel idem multiplicata , producunt jequalia; fiet multiplicando utrinque per 3 , z:X 15. Sicamp; fi habeatur

^ gt; invenietur,multiplicandoutrinqueper?,,z.x,X^'j’jamp;c. Eodem modo fi fuerit coa: quoniam, delendo denomina-

torem z.—b prioris partis^^, ipfa pars multiplicatur per x. — b:

hinc oportet etiamalteram partem a multiplicarepers,— b, ut habeatur sequatio inter ^ amp; 4 z,—ab.

Similiter fi fit^^OO nbsp;nbsp;nbsp;^ quoniam, fublato denomina-

tore

-ocr page 72-

44


Principia


tore4partisprioris^^, mukiplicata eft pars prior per amp; fit z. z.; hinc oportet amp; alteram partemnbsp;nbsp;nbsp;nbsp; miiltiplicare

perlt;ï, uthabeatur. Vnde cum xquatio pro-

K

pofitaredudafitads.?: 00 nbsp;nbsp;nbsp;?-I~*^, fi denuo utraquc

pars multiplicetur per x:, denominatorem pofterioris partis

^ X \ u h ^ (I b b nbsp;nbsp;nbsp;/.//

*--, n^lV ZO az.7iabz. abb.

Exquibuspatet, aequationem, cujusutraque pars eft frafiio, reduci ad aliam, quse fraóètone caret, mukiplicando per cru-cem, numeratorem nempe prioris partis per deaominatoremnbsp;pofterioris, amp; numeratorem pofterioris partis per denominatorem prioris. Quod idem eft ac fi binas partes tequationis ad ean-dem denominationem reducantur, ipfeque deinde, omittendonbsp;communem denominatorem, per eundem multiplicentur.

Vbi notandum, admajorem abbreviationem atque operatio-nis facilitatem, non raró turn niimeratores, turn denominatores, ante hanc multiplicationem adfimplicioresterminos reduci pof-

fe. Vt fi fuerit


axaa

a -f-a

z z—aa amp; 2: lt;jad2:—i2amp;_i,fiet nbsp;nbsp;nbsp;COnbsp;nbsp;nbsp;nbsp;.aeproinde,

fi multiplicetur per crucem ,invenietür^’ CDazz— 2 aaz-i-a^

-hb z __ aJ —ahb


reduéiis denominatoribus


Similiter fihabeatur


ZO


: reduöis numerato-


ribuslt;Z4x: — y^z. 8c a^abêgt;3.^z8c a, habebitur; fi per crucem multiplicetur, fietx:?: CO a z al?. Non fecus fi

o-ZZb z Z a aab nbsp;nbsp;nbsp;, .

habeatur nbsp;nbsp;nbsp;oo —^cum numeratores z: — y^z.

8c a a—¦ reducipoflint adx:X, amp;lt;*,ut amp; denominatores yyy^ amp;^ad^ — z8c I, fiet ^ 'p j ideoque mukiplicando per

crucem, exfurgetx,x: oo —az -\-ay.

Hue etiam refer, cum integrum sequatur fraftioni. Vt ffha-

bcatur aequatio inter ~ ^ 8c a bhb\ fubftituta enim x ï lt;1 x:nbsp;nbsp;nbsp;nbsp;a

unitate pro denominatore ipfiiis integri ayyy,camaz^'bz} 8c a bbb reduci polfint ad x;’ 8c b, erit sequatio talis


—X-,ubi ¦b K


-ocr page 73- -ocr page 74-

4(5 nbsp;nbsp;nbsp;Principia

veniat^iOOy. Sic amp; fifuerit^’ OOi2 5.,ent,extraöautrinque radi-ce cubica,?. 33 5. Eadem ratione,fi habcatur z.z.ZDlt;i^-\-iab~\~bh; extraöa utrobicjue radice quadrata,fiei z. coa~\-b. Nee aliter fit finbsp;iacntz.z.odM-^bc iaybc,tntzn\mz.ZDA ybc. Non fecusfi ata:

Fag. 6. squetur —\a-\-y^a-{-bb,cnt x CO yy y ^aa-j-bb.

His lubjunge fequens exemplum, in quo oaines prsecedentes

modi reduéfionis fimul occurrunt.Proponaturv'— --y—~

CO y : quia igitur eorum,qu2 squalia funt, sequalia quoque

fiint quadrata,fiet,multiplicando utramque partem in fe quadrate,

4

azK

-r

\z.z.y—~^---- ZD^- Addatur jamutrinque-j/ nbsp;nbsp;nbsp;^ , amp; fiib-

40 nbsp;nbsp;nbsp;4nbsp;trahatur Ip , transferendo fcilicct ipfas in alteram partem fub

contrariofignOjUthabeatur^^—folaex una parte, fietque

-co y~

Qlio fado, multiplicetur rurfus utraque

parsxquationisin fe quadrate, ut evanefcatfignum radicale; ha-

bebiturque^s.**—• Vbifi utrinquedematur

i ac rcliqute partes omnes addendo ac fubtrabendo ex una parte in alteram transferantur,quod fit mutatis tantum fignis, erit

--^4^ CD • Porröutdeleanturfradiones, reducantur

b nbsp;nbsp;nbsp;DOnbsp;nbsp;nbsp;nbsp;^

omnes termini ad communem denominatorem ^bb: quopera-do fi utrinque per eundem multiplicetur, ipfum nempc deno-rainatorem omittendojobtinebiturqd^it,'*—4 nbsp;nbsp;nbsp;CD9 bb-

Dividatur jam ubique per^, hoe eft, a, ubique deleatur fitque 4^^^*—CD 9 bh' quo fado, dividatur utraque pars pefnbsp;4 ^—4lt;« ut habcatur quantitas zy ex una parte fola , eritque

CO ^ ¦ Vbi fi utrobique extrahatur radix quadrata, habe-bitur z.z.CD\^by ¦ amp; fi denuo utrinque extrahatur radix

quadrata, invenietur z: CD yquot; nbsp;nbsp;nbsp;

E quibus patet, redudionem per additionem amp; fubtradio-

nem

-ocr page 75-

Matheseos Vniversalis. 47 nem inftitui tam ad diminuendam multitudiriem terminorum,nbsp;quam ad jequationem rite ordinandam; reduétionem veró pernbsp;mukiplicationem ad evitandas tum fratSiones tum quantitatesnbsp;furdasj amp; redudionemperdivifionem, tam ad deprimendas di-menfiones, quam ad reducendam squationem addebitamfor-niam amp; fimpliciffimos terminos j ac denique rcduótionem pernbsp;extradlionem radicis , ad obtinendam sequationetn cx minimisnbsp;terminis conftantem j pr£Etcrquam quód omnes hx redudtionesnbsp;etiam ad quantitatem quasfitam ex data xqiiatione inveniendamnbsp;utiles efle poffint. Atque hxc quidem ad introdudionemMetho-Geometria» Renati Des- Cartes dida fufEciant.

FINIS.

FRAN-

-ocr page 76-

48

FRANCISCVS i SCHOOTEN

AD L E C T O R E M.

/^^terüm ne locus fuperftes hujus pagrna: vacuus rclinquere-vifum fuit hoe loco fimul indicare fphalmata, qusein Exercitationibus noftrisMathematicis, qnas anno i^57 in lucemnbsp;emifiniusjfaeirunt commifla,ac poftmodum a nobis recognita: ur,nbsp;iisfequenti modo correftis, Leftoris ftudium in confimiliargu-mento abfque mora octuparetur.

Pag-óquot;. 1.2 \e^cpretmm.'p.’].\.% lege7»(C/?w.p.i(S^3.1.penult. lege lt;^Hlt;tJtverim:lt;p.\^ 3 .l.iz.lege milhz omntno.'^. 2 28.1.3 lege fit?.?,—zaa.nbsp;ibid. 1.penult, lege incircHmferentia.^. 295.1. 28 \egedefiriptio.nbsp;p. 3 17.1.2 2 legenbsp;nbsp;nbsp;nbsp;efire£t/4hf. p.3 27.1.4 lege Ofienfo.'ï\)l(\.\.z.n-

tep. \egeipfactrca.^. 3 29.1. 10 pro E G IcgeE C. p. 347.1. 5 pro E C,E F lege ^ C,s F.p.3 6'i.l. i.lege ad E-^ttautA Efit aejuahs A'E.nbsp;p. 372.1. antep. poUj^od, amp; p. 393.1. 9 poft ^uodeo tollcvir-gulas. p. 423. 1.13 pro 6'9 lege ^39. p. 432. 1. 7 lege 1534.nbsp;p.434. Lult. amp; p.4d2.1.3 o, ut amp; p. 480.1. 24. legeabsre. p. 471.nbsp;1.2 2 lege in locum ar a.-, p. 5 2 5. linex 6', 7,8,9, i o in locum linea-rum2,3,4, j funtfubftituend^, Seviceversl p. 527.I.21 legenbsp;Ha autem.nbsp;nbsp;nbsp;nbsp;~~

-ocr page 77-

Natura, Conjlituüone, ^ Liwitibus

Opufcula Duo.

Jncepa a ¦

ELORIMONDO DE BEAVNE,

InQuria BkfenJïConfiUario Regio ; Abfoluta ver o, ^pji mortem ejm edita

ab

ERASMIO BARTHOLIN O,

Medicinae amp; Mathematum in Regia Academia Hafnienfi Profeflbre publico.

fA M S T E L O D A M I,

ExTypographia Blaviana, mdc lxxxiii. Sumpibus Societatis,

-ocr page 78-

S VMMO MVSARVM

M.^CENATI

IlLVSTRISSIM o ET E X CE L LE NT I S SI M amp;

DOMINO,

rOACHIMO GERSDORPH

TOPARCH^ IN TVNDBYHOLM, amp;c. EQ.VITI AVRATO,

REGNï DANI^ SVMMQAVLjE MAGISTRO,

PRÏNCIPI SENATOR!,

REGIME MAIESTATIS PR^SIDI BORINGHOLMENSI

HOC

SPECIMEN ANALYTICES NOVO ARGVMENTOnbsp;€ ON S E C R A T

OBSEQVIVM.

Quod

-ocr page 79-

I Vod jam pridem in votis erat.ftudii amp; pietatis measnbsp;experimentum Tibi pro-^ ban, id recentiffima Mu-Tarum Algebra interpre-tabitur, Etli enim, beneficia maxima,nbsp;^uibus me totamque domum noilramnbsp;^nerafti,qu^m grato animo exceperim,nbsp;lï^ihi ipfe fim teftisj tarnen miferam earnnbsp;vitamputavi, cuieiTe gratam probarenbsp;antea non licuit: id aliquo obfequio ^nbsp;turn ipfi Tibi, turn casteris omnibus imnbsp;dicatum, maximeque perlpicuum eflenbsp;defideravi. Neque sequum eft, virtutisnbsp;depr^edicationem privatis tantum pa-rietibus claudi. Inter ingratos etiamnbsp;annumerantur ii, qui beneficia acceptanbsp;paucis commemorant ; totus Orbis,nbsp;adhibendus eft,pietatis noftr^ teftis amp;nbsp;confcius. Quoniam verb monimen-tum Tuarum virtu turn nulla unquamnbsp;obfcurabit oblivio j nullum erit talinbsp;Heroi dignius genus obfequii, quam

G X nbsp;nbsp;nbsp;lt;juod

-ocr page 80-

quod nulla temporis circumfcriptione terminatur. Quocirca hoc opufculumnbsp;Algebraicum opportuniflimum exifti-mavi, quod meae perpetuse obfervan-tlx teftem fempiternum confbituerem •nbsp;in quod baud obfcurb conjicio, nihilnbsp;fenedtuti, nihil fucceflbribus licere.nbsp;Mirandam Algebrse vim multis verbisnbsp;exponere fupervacuum eft, quippe fe-cura demonftrationis fuas, Temper amp;nbsp;pacis amp; belli ferviit artibus; in qua hocnbsp;eximium eft, quod abundantiasdefe-dlusque pari momento ^ftimet, nequenbsp;illi, quae plus habent, magis neceftarianbsp;flint, quam quae minus; atque hocfuaenbsp;fcientise habet monimentum , quodnbsp;mortalesfaciunt Virtutis. Verum, ar-tium amp; fcientiarumincrementa, non innbsp;ipfarummodo ingenio, fed etiam in fu-periorum dementia fita funt; ^eftiman-tur quoque pleraque mortalium pre-tio, quod libido calumniandi confti-tuit 5 amp; quis neget, eximium decus,fae-

pius

-ocr page 81-

pius favoris, quam virtutis eJTe beneficium ? unde patrono ¦amp; defenfore iis opus eft, fubcujus aufpiciis floreant.nbsp;Algebrie nihil adaugendumfaftigiumnbsp;fiupereft,hoc tarnen uno modo crefcerenbsp;poteft. Te ergo praefertim invocat,cu-jus cepimus amp; affedus amp; judiciiexpe-rimentum, quantum maximum Mufenbsp;oapere potuerunt. Indulgentie Tuenbsp;propinquum exemplum eft Aftrono-mia, quam in Tuo gremio fufcepifti,nbsp;cum naufragium illud obfervationumnbsp;Tychonicarum, quas invidiosa tran-quillitate provedas improvifus turbonbsp;abftulerat, Tuabenignitaterefarcires.nbsp;Tuo beneficio patriam receperunt. T a-ceo literas Graecas,quas majoribus fuisnbsp;ita reddidiftijUt ille utrum plus Tibi,annbsp;Tu illis debeas ambigipoflit. Et ut ver-bo abfolvam:,Tue benevolentie ufumnbsp;nec litteris nec hominibus unquam de-negafti. Quare illud extremum oro, ut

eidem Generofitathcui tribuifti hoc.ut

G 3 nbsp;nbsp;nbsp;lite-

-ocr page 82-

literas fufcipcres, attribuas, ut fufce-ptas tuearis ac foveas: atque hoe grati animi, non omnino quale velim, fednbsp;quale poflum hoc tempore monimen-tum, favore excipere digneris. Cele-bratum eftfama amp; acclamatione quantum Aftronomiam amplificaverit Da-nia^ Tibi verb renafcentis Aftronomiamnbsp;gratia debetur. Et fipropofito annue-ris, non tam patrise qu^m Tibi debito-rem conftitues etiam Algebram, hoenbsp;eft.Mathefin Vniverfalem. Ego floren-tem virtutis Tu^e gloriam aeternam o-pto, Tibique feliciflimos annos preca-tus,in clientelam Tuam receptum efte,nbsp;fupra humanum folatium recreabor.

Hüfnix, jimo cIdIdclvii.

Erasmivs Bartholinvs, Medicinse amp; Mathematum Profcf^nbsp;for Regius.

-ocr page 83-

ErasmI Bartholtnï AdTr3fi:atumdeNaturaamp; Conftitutioncnbsp;itquationum

EPISTOLA PRjELIMINARIS

Clürïjjlmum Vïrum

CLAVDIVM HARDY,

Regis Galfiae Confiliavium.

; V(tm'üis fnifirahujm feculi judkiafarum I afud me 'valeant, tarnen d divulgandis e~

I jufmodi quemlihet jure abfierrerent, qudt diverfM hominum cenfaras •vitare ne~nbsp;yerümego alto faperctlio fpretis cdmnnm^nbsp;^quitatis amanüor ^-jgtthïtCie Mtilitatis, -profojitanbsp;dejtjlere nolui, tibique^ P^ir Qlarijjime, exponere con~nbsp;fittui^ea^q^fde adpr^efationem utilia ejfeputa'vi^ eo li~nbsp;bentiuSj quo cogntyverim amiciffimumtibtfuijfe, dumnbsp;invvvu eJJet,I).De Beaunedn Quvia Blefenfï Conji-tiarium Regium. Nam etjï^ir hufnerit perelegantinbsp;jngenio^amp;in tantum laudandus^n quantum intelli-gi virtuspotefi 5 tarnen hoe in eO'maximum fuit-, quodnbsp;^Nlathemata doBiffimm -, ut tempore aqualis Vironbsp;fummo Lgt;, Des-Cartesy ita ^naljtices fpeciofie perknbsp;tta proximus. G^uo momento impuljus, dum Blejïisnbsp;linguae Galtica. exercendre gratia degerem^amicitiamnbsp;tanti Niri colui, diligenterque ed famitiaritate ujmnbsp;fum, qua ipfe me comiter ampleBebatur. Interea denbsp;^ebm Mathematicis omnk ferè fermo, ÊT quoties

alter-

-ocr page 84-

alterutri de Andyticis férmocmari 'volume, toües fiofira conferri colloquia necejje er at. nde non oh-^nbsp;fcurè intellexi, quantis fuerat ingemï dotïhus acftu-diorum emïnens, a quo, Jifublica negotiafermitte-rent , qgt;erfeBiO udlgehne maxime f^erari pojfet.nbsp;Qjiare variisprecibus hortatusfum.^ ut^^qua. medita-tus er at.) publicisdefiinaret u^bus. erum ille muLnbsp;tajïhi obfiare, occupationes tam publicas quampp-quot;vatas j ’valetudinem, operas amicorum, ea deniquenbsp;principia, qu^ ad intelleBum fuarum meditationumnbsp;necejjaria erant., dejiderari innuebat. 'Turn ego, ^nbsp;me am operam ipjipolliceriparatijjimam ccepi, '0^jï~nbsp;gntficare confcriptam effe a me Ifagogen Qartejta-nam, quorum neutrum propojito mor am ajferre diu-tius pojfet. ^mbus 'valde recreatm, de edendis ope-ribus fuis ferio cogitabat. Sed, cum Arthriticis do-loribus plus folito, leBo detineretur, omnem d Ala-thematicis.) ad corporis ualetudinemcuram trans-ferre cogebatur. Ego interim ad perlujirandas reli-quas Gallis proAncias avocatus , per aliquodnbsp;tempus fubfliti Flexie ‘ unde, cum 'varia negotianbsp;re'verti Lutetiam fuaderetit, placuit Cafirum Ble-fenfe tranfire., ut de fanitate amici certior jierem.nbsp;Qjiem in pradio fuo, cum doloribus Colicis acriternbsp;confliBantem, cum deprehendijfem, 0* ajfirman-tem parum projperd 'valetudme ex eo tempore fe u-furn fuijje; ?Jon mediocriter dolui, egregiis in'uentisnbsp;fortunam tam ejje adverfam: mea verb fiudia ite-

ratb

-ocr page 85-

rato ohtulij jproftiittens^me honofuUkOy ejufque gratia , quafüis fuUturum moleftias. Sedfof^quara re-laxationis morbi nulla affulgeretffes, fujfh ans 'va-ledixi, iterque fufieftum ingrejjus, Lutetiam rean. Vtxibi confuetafiudm revocaveram, mm liters mt-hi redderentur ah hofpte meo, Viro humaJitifmOynbsp;D. Antonio Mar chats, inurhe Blefenje tune linguanbsp;Gallier Profejfore, tmnenjero Serentjjinn Prmctpsnbsp;Gaftonis, Ducis Aurelianenfium ¦, Mathemaüco^nbsp;quibus nunttahatur, agrum nojlrmn, oedorum ufunbsp;privatum fuijfe, temporihus folfiitii Brumalis, abnbsp;acrimonia defi'uxionis Arthritic^ ; exoptajje ’veronbsp;meam pr^fentiam tanto dejiderio, ut de edtüone co-gitationum fuarum defperaret, wji me a opera uitnbsp;pojjet j adeoque rogajje, niji grave nimis ejjet, ope-ram quam pollicitm er am accommodarem. Exarfe-rat ea tempefiate helium civile inter Regent Galli^^ •nbsp;Principes confanguineos , fedefque exercitusnbsp;Principum er at Stampa , quam ohjidione aggredte-hatur Dux exercitus Regü. Hac cum tranfeundemnbsp;ejfetiis, qui ad Comitatum Blefenfem per gunt; an-cipiti cura difiraBm, conflitueram tarnen longiffimisnbsp;viarum ambagibm, per Normanniam Eucatumnbsp;^Mndegavenfèm potiusiter moliri, quam fpes ann~nbsp;ci defer ere. Gquippe ea pars territoriï Parifienfis,nbsp;Rothomagum versus, tantum militibus vacavit.nbsp;Gum inexfpeBato , propter adventum exercitusnbsp;Lotharingici, folutd obfidione Stampa , ager Gafunbsp;Pars 11,nbsp;nbsp;nbsp;nbsp;Hnbsp;nbsp;nbsp;nbsp;nenfisy

-ocr page 86-

nenfis^milite utriufcjne fartis Uheraretur quot;pradonu hm tarnen infeftari was jignijicatum efi. Gluare ar^^nbsp;reft a occajione^diffuadentihus amutsdtïneYÏ me com^nbsp;mtfijfar'vi aftimans^unoferkuloy^ amicofrodejje,nbsp;Qf f radar a invent a r e dimer e. Neqne primas fpesnbsp;for tuna defiituit j quippe emenfo periculojijjimo itine-^nbsp;re jfalvus revijt amicum^corporefdtis fanum, niji lmnbsp;men oculorumrapuijfet agritudo. Sed duhiumitine-ris eventum deteriorfortuna excepit 5 cum inprimor--dio nofirorum operum-,forfan qmd diligentim^quamnbsp;permitteret anni tempus ¦, yllgebraïcis fubtilitatihusnbsp;incumherem^ aftate media,Jummkcaloribm,/ub Ca-^nbsp;niculam^ ingravijjimum morbum exfebriJ^nocho in-ciderem. Et jam de me a falute defter antibus Aledunbsp;cis , inopinatü animam effavit JEir Amplijfimmnbsp;D. De Beaune. Nam^ cum amico aliquoquileBonbsp;ejm ajfiderat., de rebus Analjticis dijferentem, fubitonbsp;defiituit vox, deinde totum corpus vitalis calor re^nbsp;liquit, atque evafit perpetuam valetudinem dienbsp;19 udugufii.^ u4nno lóji, natm Anno 1601 dienbsp;17 Sept. Sic pracipitantibus fati^ , fefellit Jpesnbsp;omnium mor talk as. Ego^ cummihi indicariincon'nbsp;fultum ducerent noflriy dum morbus nondum declina^nbsp;ret j ne agritudinem aggravarent, non niji pof mul'nbsp;turn tempus id refcivi. Eum nihil cunBatus., opera0nbsp;dedi, utfidei me a committer entur , qua reliBa fuC'nbsp;rant adverfaria, nullam curam mortuo detreBan^tnbsp;quam vivo definaveram ^ publica utilitatis ratiO'

-ocr page 87-

nemhahitarm. ReluBantihus njero h^redihus ^ cum alius pecunia JblicitaJfet animos eorum-, ^arumah-^nbsp;fuit, quin idem fcripta, qui auBorem, ca/us traxif-fet. Ergoomni fiudio demonfirare occcep ^ periturosnbsp;omnes defunBi conatus nifi mihi traderentur; fpar-^nbsp;fas chart AS-, fine or dine yjtne numero, Jïne explicationnbsp;ne, notisnbsp;nbsp;nbsp;nbsp;charaBerthus exaratas fopputationeSy

non ah alio intelligi poffe, quam qui aliquo tempore cum ipfo familiariter 'vixifet. Gpuihus perpenfis,nbsp;tandem obtinuipropojitum, fed majori laborCy quamnbsp;Juccejfu. Gpuippe omnia diligentius infpiciens, animquot;nbsp;advertiplura affeBata quameffeBa. Inter tot ad-quot;verfaria folummodo abfolutum in^veniopus de Angulo Solido, quod jam pridem in publicum edidijfemynbsp;nifiJumptus, propter copiam figurarum, Bibliopolenbsp;fafiidiviJfent.EraBatus de Natura 0^ Co?jflitutio-ne yEjquationum ne liter a quidem extabat, mentinbsp;tarnen D.de Beaune pier aque conformia ejfe differ en-do dum licuit cummuo comperi. Ex ik, que de Li-mitihus jEquationmn confcripf, quedam repertanbsp;funt in adnjerfariis, qmbus, cnm multa defideraren-tur y ultimam manum imponere neceffe habui. Pre-fationem denique , quam Author huic operi pre-mittendam duxit y nereligio ejfet omittere, addidi.nbsp;Non ignora/s, Vir Clariffime, me rogatu Authorisnbsp;omnia G alike prius confcripJiJfeytibiqueQf aliisper-legenda dedijje Qf corrigenda j tarnen nunc Latinènbsp;cdere coaBusfum, ne diutius laterent, Nam etji tihi

H 1 nbsp;nbsp;nbsp;dum

-ocr page 88-

dum in Italia degerem, adeh cordifrerit horum fcru ftorum d me tibi reliBomm editio , utfumptihus pro-priis excudi -^arares ¦, quo nomine multum tihidebe-^nbsp;buntpofieri j tarnen ne in Gallia quidem 'votum ajfe-cutm es. GgHocirca, cum Am^elodami iteratopr^^nbsp;lo fubjiceretur Geometria Renati Des-Cartes , idnbsp;operam dedi , ut h^c und imprimerentur. Cow-fentiente •verb quot;Tjpographo modo Latinè exta--rent, placuit Latinam interpretationem in co?tJt^nbsp;Hum adhihere , 0^ potius authoris precibm inobe^nbsp;diens , quam publici negligentior reputari. Gpuodnbsp;perpendendum relinquo iis , qui me •violate fideinbsp;tacitè accufabunt. Subjunxijfem alia , quorum ue-ftigia adhuc fuperfunt in adverfariis, fid quidamnbsp;tanti indigent laboris y ut de reflitutione quafidejpe^nbsp;rem , alia remoratur multitudo figurarum : cun^nbsp;Ba tarnen brez!i Adebit beneuolm LeBor, fiTy-pographi obedierint. Interea hifiefruere^ tuque Firnbsp;Clartjfime y judica quid ex meiscurisy ^ difjicillunbsp;mis itineribus , fruBus colligi pojjit, tuum namquenbsp;judicium erit injiar omnium. Qmd fi tarnen 0* aliïnbsp;confiteantur , him non exiguum emolumentum adnbsp;omnes redundarey rogo ut id Adanibus yiri Cla-riffimi Florimondi de Beaune acccptum refer ant;nbsp;err ores quot;verb fi offenderint, benigne corrigant, me^c-que humamtati aCcribant. Vde..

FLO


-ocr page 89-

FLORÏMONDI DE BEAVNE

P R iE F A T I O.

Ecreveram in publicum edere hofce traótatus , multb prolixiores atquenbsp;perfeéliores, proximo infèquente anno. Verüm anni hujus initio confli-^tatus cum gravifïïmo ad oculos defluxu, ocu-lorum ufu privatus fui. Vndepropofito planenbsp;deftitiffem, nifiL D-Erafmius Bartholinus opc-ram mihi fuam, ne mea circa hanc artem in-venta oblivione fepulta jacerent, obtulilTet.nbsp;Ejus igitur auxilio hoe opus compofui, ad quodnbsp;intelligendum luppono Le6tores jam in Geo-metria Renati Des-Cartes verfatos, additisquenbsp;in earn Notis, a nobis olim (non quidem animo illas in publicum edendi) concinnatis 5 ut 8cnbsp;doctilTimis Francifci è Schooten Commenta-riis j nee non Principiis Mathefeos Vniverfalis,nbsp;feu Introduótione ad Methodum Geometria:nbsp;Renati Des-Cartes, ab eodem Bartholino edita.

H3

TRIOR

-ocr page 90- -ocr page 91-

^3

NATVRA AQVATIONVM.

C A P V T I.

Vltó faciliüs inveniemus Naturam amp; Con-ftitutionem iEquationum ex earum gene-ratione amp; comparationecum fimilibusfeu ejufdetn forms, quam conferendo carumnbsp;radices cum certis mediis Geometricè pro-portionalibus ,utprsftititViëta.

jïquationes autem facilitatis gratia ita difponere libet, ut omnes termini abunanbsp;parte reperiantur squalesnihilo, ponendo ipfos ordine, proutnbsp;gradatim per incognits quantitatis dimenfiones defcendunt. Pri-mum enimterminum vocabimuSjipfam quantitatemincognitam,nbsp;qusplurimarum dimenfionumexiftens nullis aliisquantitatibusnbsp;adficitur j fecundum verb, in quo incognita quantitas una dimen-fione minor eftjtertiumin quoduabus; amp; fic deinceps,ufqueadnbsp;terminumomnino cognitum , quem pro ultimo habcmus. Deinde, loca, ubiterminorum aliqui deficiunt, afterifco complebi-mus, qus tum fub numero terminorum comprehendentur, Hscnbsp;omnia beneficio tranfpofitionis facileperaguntur.

Ex iis, qus fcripta amp; commentatafunt in GeometriamRenati des Cartes, nota eft methoduscognofcendi, quothaberi portintnbsp;radices in qualibet ^quatione: nimirum, pofle ^Equationem totnbsp;habere veras radices, quot mutationes fignorum continus adfue-rint,^amp; quoties eademfignafeinvicemfequuntur immutata, totnbsp;pofle reperiri falfas radices: modb in numerum terminortinaiinbsp;numerentur, qui deficiunt.

Porró, duas iEquationes fimiles efle dicimus feu ejufdem forms , quando in utraque idem eft primus terminus, amp; reliqui termini in utraque fimiliter funt affefti; amp;fi in una terminus ali-quis abfuerit, ut is quoque abfit in altera. Nam cum fimiles funt iEquationes, eandem habebunt conftitutioneni amp; naturam, Scnbsp;fieri potcrit comparatio feu collatio fingulorum terminorum u-nius cum fingulis terminis correfpondentibus aiterius,

C A-

-ocr page 92-

64

De Nat

C A P V T II.

natura amp; conflitutione (^_/^o[iiationtm ^adra^ tarum, feu duarum dïmenjiomm.

Vando ÈEquationes hs fant afFedï , reducuntur omnes ad ^ tres formas fequentcs:

XX lx—mmCO o XX—lxmmCDonbsp;XX-'lx mm zo o.

I '^ropojitio.

Ad intelligendam naturam amp; conftitutionem prioris scquatlo-nis, formeturper multiplicationemharum duarum x~- hzDoZc X 4- c 30 o fequens aequatio: xxbxbc ZO o- Supponendo

c

igltur c majorem quam b, eandcmhabebit formam atque prima proporuarum;^ AT 4-/;»; —mm 30£3. amp; per confequens, bin£E Hjenbsp;grquationes eruntejufdem naiur$ amp; conftitutionis. Fiatcollationbsp;unius cum altera; amp;per comparationem terminorumfecundo-rtimhabebirnus c—'bzo l- Vnde difcimus, /cfle differentiam inter falfam radicem £•amp; veram amp; , cognita hlsac, yeram^elTenbsp;sequalcm ipfi c—/; amp;, cognita yera ^ , talfamt-effeaequalemipfinbsp;h-\rl-

Prseterea, ex comparatione poftremorum terminorumhabe-bimus mm atqualem bc. Vndefequitur mm effexquale reftan-gulo fub vera amp; falfa radicc; amp;, cognita falsa c, veram b xqualera

efle ; amp;, cognita vera b, falfam c tequalem efl'e nbsp;nbsp;nbsp;.

a ^rofofitio.

Pro fecunda aequatione propofita formetur rurfus per multipli-cationem duarum x—bzoo Sc a;4-£-30 o,sequatioxv—bx—bezo o.

¦^c

In quafifupponamus b majorem quamc, eritipfaejufdemfor-mse cum fecunda propofita xx—lxmmZO o. Etperconfe-quens dua; illa: $quationes erunt ejufdem naturse amp; conftitutionis. Facftaergo colJatione unius cum altera, habebimusex col-

latio-

-ocr page 93-

^ V A T ï o N V M. nbsp;nbsp;nbsp;65-

lationcfecundorumterminorumc—bzol,ve\lzoh~^c. Vn-de difcimus, quod /eft differentia inter veram radicem b amp; falfam c-, amp;ficognita fueritfalfac, eritvera^2Equalis/ t-j amp;fïfueritnbsp;cognitavera^,falfameritsequalis ^—l.nbsp;nbsp;nbsp;nbsp;•

Porro, per compaKationem poftremorum terminorum , ha-bebimus mmZD bc. Vnde fequitur mm cffe squalerediangulo fub vera amp; falfa radice; amp;, cognita falsa c, veram b effe squalem

amp; gt; cognita vera b , falfam c effe CO

3 'Pro^ojiti’0.

Pro tertia fupra pofita a:quatione, formemus, per raultrplica-tionem duaruma?'— bzoo amp; x — ccoo, aïquationemfequentem XX—^a; ^cC0 O)amp; habebiteandcmformam atquepropofitanbsp;c

tertiaar^V'—Ix-^-mmZDo^ amp; confequenter hsebinssquationcs erunt ejufdem nature amp; conftitutionis. Comparemus ergo unamnbsp;cumaltera, atqueex collatione fecundorum terminorumhabe-bimus ^ cOO /• Vnde difcimus, qüod/eftfummaduarum vera-rum radicum, amp; fi unaearum , exempli gratia, c, eft cognita, re-liqua è aequabitur ^—c.

Prseterea ex comparatione ultimorum terminorum habebi-musmm'Xtbc,hoe mmatqualereclangulofub duabus veris radicibus, quarum fi altera tra eft iiota, exempli gratia, c, altera bnbsp;lt; , m m

a^quabmir .

Quantum ad ïquationem quadratam xx •—wwCOo, qu$ non eft afFelt;fta ,ipfa oritur ex duabus fequentibus AT — ?wOD o , amp;nbsp;x-^mZDo. Vnde fequitur ipfamduaspoffidere radices, unamnbsp;Veram, alteram falfam, quarum utraque xquatur ipfi m.

C A P V T IIL

natura ^ eonflitutione (:_/Equationum Cubic arum feu tertia dimenjionisfecimdo terrmno carentium.

¦ mmx-¦mmx-

/^Mneshs xquationes reducuntur ad tres fequentes fprmas : x^^ -^mmx — CO o.

3*.

CO o.

11.

-ocr page 94-

^6 nbsp;nbsp;nbsp;DeNatvra

I Tropjitio.

Ad cognofcendam naturam amp; conftitutioncm prioris arqua-tionis propofitk , formcmus per multiplicationem harum dua-rum xx^hx-^ccTDoècx — ^CDO hanc aequationem — bbxbccTDo. Suppofitoautcra cc majori quam^

CC

ipfa eandem habebit formam atque prima propofita * «?«?ar —nbsp;nbsp;nbsp;nbsp;00 o. amp; per confequens ejufdemerunt naturae amp; conftitu-

tionis. Fiat igitur illarutrt collatie, amp; per comparationem tertio-rumterminorum babebimus ccbbTDmm. Vndeconftat, fi vera radix b cognofcitur, cc foreaequale wnbsp;nbsp;nbsp;nbsp;amp;confe-

quenter ara:-f-^ ar00 o. quaeaequatioduasreliquas radices refpicit, ac cumvera radice b concurritadformandatnnbsp;aequationem propofitam.

PrjEtcrea, faólacomparationcultimorumterminorum, habe-bimus»’ ZDbcc. Vnde fequiturccefleaEquale^ j amp; , cognita

vera radice^, hanc aequationem ara; ar oo ofirailiter

duasreliquas radices refpicere, amp; cum vera ^ concurrere ad for-» mationem propofitae aequationis.

z Tropojitio.

Pro fecunda aequatione propofita formetur rurfus per multiplicationem duarum xx-\-bx-\-ccZDoamp;cxbzo o aequatio —bbxbccZDo. Suppofitoautcm^^majoriquamccjba- cc

bebit lila eandem formam atque fecunda ar* ^ —m mx — »* 00 o» amp; per confequens babebunt eandem naturam amp; conftitutionem.nbsp;Fiat igitur collatio,amp; ex comparationc tertiorumterminorumba-bebiraus bb—ccoomm. Vnde conftatj c c effe jequale bbmm; Ar,nbsp;cognita vera rad ice ^,tequationem banc ar ar ^ x-^h b —m mZOonbsp;duasreliquas radicesconcernere. Porro,excomparationeduo-:nbsp;rumpoftremoruinterminorum, babebimus»* ZO bcc, undcfc-

quitur cc efl'e aequalc ~ ; amp;, cognita veriradice b, banc squatio-

ncraxx bx-i-- funiliteradduasrcliquasrefpicere.


-ocr page 95-

iEQ_VAT10NVM. nbsp;nbsp;nbsp;6j

3 Tro^ojïtio.

Ad invcnlendam naturam amp; conftitutioncm tcrtia: acquationis propofitXjfiatexduabushifceA-ar ^Ar'—cc ZO oamp;c x—bzDonbsp;«quatioAT^* — bbx-{-bccZO o, eaodemhabens formamcura

¦—'CC

tertia propofita — mmx n^ZDO. Vnde amp; ipfxeandctn habebunt naturam atque conftitutioncm. Fiat ergo collatio, amp;nbsp;per comparationem tertiorum terminorum habebimus bb-{-cc ZO mm. V nde conftat, c c squale efle mm — ^ ^, cogni-ta veraradice by xquationem banc xx-\-bx’^bb—mm ZO onbsp;ad duas reliquas radices refpicerc.

Prxterea, excomparationcpoftrcmorum terminorum, habebimus GQ amp; pcrconfequenscc CD ^ - Quarcjcognitave-

raradice^jhxcxquatioATAT ^A:—^ CD o fimiliterduas reli-quas radices concernet.

C A P V T IV.

2)e natura ^ conftitutione z_/Equatiomm Cubic arum feu trium dimenjiomm, tertio termino carentium.

HJS. xquationes reducunturad tres formas fequentes:

/xa:*'—CO o. x^Ixx^—CO o.

AT*—/a:a?* »^ CD O.

I Tropjïtio.

Pro natura amp; conftitutione primx propofitionis, fiat per mul-tiplicationem harumduarumAAr CAr ^c30 o amp; a; — bZDO bxc xquatioAT^'—bxx* ~bb czoo. Et fuppofiu c majorc

c

quam b , habebit ipfa eandem formam cum prima propofita aJ-^-Zatat* — «’co o,amp;:perconfequenserunt£jufdemnaturx.

Faftaergo collatione, babebimusex comparatione fecundorum terminorom cbzo^, boe eft, cZDl-\-b. Vnde conftat, co-

1 z nbsp;nbsp;nbsp;gnita

-ocr page 96-

6-8 nbsp;nbsp;nbsp;DeNatvra

gniu vera radice ^jsequationem nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp;duas

reliquas radices refpicere.

Prseterea, ex comparatione duorum ultimorumterminorum, habcbitur/ï^GO^^c. undefequitur c ede sequalem amp; ,cognita

radioed,aequationemxx ^ AT CO o duas reliquas radices concernere.

z Tropojltio.

Pro feciinda propofitione fiat ex muldplicationeharum dua-rura X X cx bc co o 8c Xb CO o hsec atquatio —bxx^bbcCO o. Et fuppofita^majorequamceritejuf-

c

demformae cutn fecunda propofitarum x’ —Ixx*—co o y adeoque erunt ejufdem naturae amp; conftitutionis. Fadia igiturnbsp;coilacione, ex comparatione fecundorum terminorum habebi-mus^ — ccol- Vndeconftat, celleatqualem ^—/; amp;, cognitanbsp;vera radice ^jXquationemhanc xx-^bx-^bb — blCDo duas

/

reliquas radices refpicere.

Porró per comparationem poftremorum terminorum habe-* bimus yigt; co bbc. Vnde fequitur c efl'e sequalem j-y-, 8c , fi vera

radix fuerit cognita, banc squationem xx x ^ CD o duas reliquas radices concernere.

3 Tropq/itio.

Protertia propofitione formemusex duabus xx—cx—bcCDo 8cxbcoo hanc«quationem x^ — cxx *-f-^^cCD o, quae

b

habebit candemformam atque tertia tequationum propofitarum — Ixxnbsp;nbsp;nbsp;nbsp;CD O , amp; per confequens erunt ejufdem naturx

amp; conftitutionis. Quare fada collatione, per comparationem fecundorum terminoru m habebimus c ^ 00 /. Vnde difcimus,nbsp;quod esquetur /—b-, 8c, fi vera radix ^ fit cognita, quódaequa-tio XX —bxbb'— ^/cooad duas reliquas radices inveftigau-

das referri debeat. nbsp;nbsp;nbsp;Pra:'*

-ocr page 97-

iE Q_ V A T I o N V M. nbsp;nbsp;nbsp;^9

Praeterea, comparatisultimis terminis,habebimusw’ unde fequitur c jeqoarinbsp;nbsp;nbsp;nbsp;, cognira vera radicc b, hanc seqiia-

tionem^ar— nbsp;nbsp;nbsp;x —¦% CO o reliquisduabusinveniendis infer-

bh b

vire.

C A P V T V.

‘De natura conjlitutime t^yEquationnm Cuhicarum feu trium dimenjiomm, in quibus omnes termini extant.

po Quationes bat reducuntur ad feptem formas fequentes;,

lxx-\~mm X — w’oo o. x^ Ixxmmx —nbsp;nbsp;nbsp;nbsp;00 o.

—Ixx —mmx — qq q. x^-^Ixx-\-mmx—»’0Oo.

^3-Ixx a; «3 3Q Q,

x^-\-lxx mmx-^n^ 00 o.

mmx-j^ngt;-:qo.

I quot;Propoftio.

Ad cognofcendam naturamamp; conftitutionem primae propo-fitionisjfiat ex multiplicationeara: — cx-{~ddo^o perx—b OOo, atquatio fequens x^bxx-^-dd x—b dnbsp;nbsp;nbsp;nbsp;o.atque eandem ha-

—c bc

bebunt naturam amp; conftitutionem. Faöa ergocomparatione, cx collatione fecundorum terminorum habebimus ^ e 00 /, velnbsp;cOO Ib. Deinde ex collatione tertiorum terminorum habebimus dd-^bc zo mm, hoe eft, ddzomm bbb /,quoniam enbsp;eft inveuta ïquari lb. Vnde apparet, cognita vera radice b,nbsp;sequationem hanc xxlx-\-mm-\-bb—blzoo duas reliquas radices

refpicere. Deniqueex collatione poftremorum terminorum habebimus bddzon^- unde conftat, d d squari ^ •, amp;,cognita vera

radice h,aequaiioncmhanc xx — ^ CO o duas reliquas ra-

•^b

dices concernere.

a VrQ-

-ocr page 98-

De Natvra

^ Tropojiüo.

Pro fecunda propofitarum fiatexmultiplicatione xx-^-cx-y-per A-—b OOo EequatiohjEC^’ —bxx'bcxéddcoo,

c d d

amp; fuppofitaemajorequam by amp; ^ r naajorc qua-n nbsp;nbsp;nbsp;habebitean-

detn tormam , qiiatn propofitio lecunda x^-\rlxxmmx — CD o , amp; conleqiicntereruntejufdemnatursc amp; conftitutionis.nbsp;Faéla ergo adaequatione , ex comparatione fecundorum termi-norumhabebimusiT—^ oo/^hoc eft,«-C0/ ^- Deinde excol-latione tertiorum terminorum habebimus ddbcZD—nbsp;hoeeft,reftiento valoreipfiuscinvento,habebiturddzo bl-\-bbnbsp;mm. Vndeconftat, cogniu vera radice^, hanc xquationemnbsp;xx lx b b-\-bl—m m'Xto duabus reliquis radicibus invefti-

^ nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;n

gandis effe utilem. Denique , ex comparatione pouremorum terminorum,habebimus^ddX n'. Vndefequitur^lt;s(foresqua-

letn ^ j amp; ,

xx-^-bx-

/

cognita vera radice i , xqaatianem hanc

^ 00 o reliquis duabusinfervituram.

3 Trofo/kio.

Pro tertia propofitionc,fiatex muitiplicaiione A:x4-e.v dlt;j?ooo per ar — ^CDo eadem aequatio ar* — bxx

¦bddeo o.

bcx'

-f- c nbsp;nbsp;nbsp;dd

EtjRippofita^majorequam e, amp; ^emajorequam dd, eritejuf-dem forms cum tertia propofitarum x’ —Ixxmmx—w*0Oo, amp; confequenter ejufdem erunt naturx amp; conftitutionis. Faélanbsp;ergo adsquatione, ex collationefecundorum terminorum habebimus c— ^OO — /, hoe eft, cZDbl. Deinde ex collationenbsp;tertiorum terminorum habebimus dd—^cOOw?»?, hoe cft,fub-ftituto valoreinvento ipCias€,er\tdd'CO bbblmm. Vndenbsp;conftat,quod,cognita vera radice b, hsc squatio xx-^bx bbZQO

—• / ——

'—mm

ad duas inveftigandas reliquas adhiberi polTit. Denique, ex collatione

-ocr page 99-

^Q_VATioNVM. nbsp;nbsp;nbsp;71

lationc poftrctnoram tertninoram, habcbitur nbsp;nbsp;nbsp;Vndc

fequimr,^xquari ^ ; amp;,cognitavcr5radice^,hancsEquatio-ncmA;;lt;' ^Ar !^ CD o ad duas rdiquas quxrendaseflc utilem.

4 Tropojitio.

Pro quarta propofitarum fiat ex multiplicatione per XbzQ o eadetnstquaiiox^bxx~h cxbddCD ogt; Et

4*c dd

fuppofitae majorequam^, Sc dd majore quam ^ £•, cruntejuf-demformsacquartapropofitio^t^ lxx »imx—CO o,amp; confequenter ejufdem nauirs amp; conltimtionis. Fadla ergo ad-squatione, ex collatione fecundorum terminorum habebimusnbsp;c—bcoli feu e CD / ^. Deinde , ex comparatione tertiorumnbsp;terminorum,habebimusddbcCO mm,hoe eft,rcftitutovalo'nbsp;reipfiuscinvento,critddcobb bl mm. Vndeconft.at,co-gnitaveraradices, hancsquationem xx-\-bx-\-bb-\rbl-\-mmCDO

duas rcliquas radices refpicere. Denique ex collatione poftre-morum terminorum habebimus èd doo»’. Vnde fequitur,dd fo^

resquale^ ; Sc , cognita vera radice b, hanc squationem afAT-F^Ar ’i' CDoadindagandasduasreliquasadhiberipofle.

5- Tropofitio.

Pro quinta propofitione fiat ex multiplicationexArcxddooo pera;/-CDo squacioa:^cxxddx ddbcoo. Etfuppoiito ^ cnbsp;b bc

majore quam d d, crit ejufdem forms cum quinta propofitarum

x^Ixx mmx n^ ZD o,Si confequenter ejufdem naturs amp;

conftitutionis erunt. FaAaergoadsquatione, ex comparatione fecundorum terminorum, habebimus ICO c b, vele CO Ib.nbsp;Deinde, ex comparatione tertiorum termmoru o , habebimusnbsp;bcddCD mm, hoceft , reftitiitovaloteipfiu-emvenro, critnbsp;dd X hlbbmm, Vnde difcimus, ct'g..ua radice vera b,

SE qua-

-ocr page 100-

D E

aequationem hanc xx-


71


N

-Ix' ¦ b


A T V R A .

— bl-\-bb-\~mmZD o duabusrcH-


quis inveniendis effe ufui. Dcnique ex collatione poftremorum terminorum habebimus 30 bdA. Vnde colligitur dd sequani

jamp;,cognitaradiceveia4hancasquationem^;t—lx—j coo

•\rb

duabus reliqms inveniendis infervire.

6 nbsp;nbsp;nbsp;^ro^qfitio.

Pro fextapropofitione formetur ex duabus xx cx—ddcoo Sc XbZDO aquatioa;^ -i-cxxddx •i~ddb00iiO.Et,[iippofn^nbsp;—b —bc

cmajoriquam^, habebit ipfa eandem formatn atque fexta pro-politarum x^ lxxmmx n^ ZD o,8c per tonfequenserunt ejufdetn naturaï amp; conftitutionis. Fiat jam comparatio, amp; ex collatione fecundorum terminorum habebimus l CO c •— b , feunbsp;czol b. Deinde ex collatione tertiorum terminorum erit mmco.nbsp;dd bc, hoe eft,fubftituto valore e invento, habebitur ddzommnbsp;•— b lb b-^ Vnde conftat, ü vera radix ^ fit cognita, hanc sequa-tionem xx lxmm zo o, pro duabus reliquis inveniendis

•\~b -\rbl

^bb

ufuifuturam. Denique, comparando ultimos terminos, habebi-tavLsddb ZO n^‘ amp; pet confequens ddzo -y adeoque, cognitl

veraradice^,haeca:quatio Arar-F/x— ^ ZO o adinveftigandas

b

duas reliquas ucilis erit.

7 nbsp;nbsp;nbsp;Trüpojïtio..

Pro feptima propofitione formetur ex duabus xb ZO o Sc xx-^cx—d dzo QsquatioAf^-FcA;x—ddx ddbzoo. Sup'

b nbsp;nbsp;nbsp;—bc

pofita autem b majore quam c , habebit ipfa eandem formam cumfeptimapropofitaruma:^ —Ixxmmx-\-n^ ZOo, amp; con-fequenter erunt ejufdem natur* amp; conftitutionis. Faöa igiturnbsp;comparatione, prictur ex collatione fecundorum terminorum,

/GO^—

-ocr page 101-

j®q_vationvm. nbsp;nbsp;nbsp;75

l^Xih—c, feu c 00 é — l- Deinde, conferendo tertios terminos, eritmmo:gt; èc dd,hoeeft, fubftituendovaloremcinventtim,nbsp;habebitur ddco»imhb-^bLY nde difcimus,cognita vera ra-dicc^, Wanexquaiionemxx bxmm-i-bb—^/oooadin-

/

veniendas duas reliquas infervire. Poftremo, collatis ultimis terminis, habebimuslt;5/W^ X unde erit öf^arqualc^ ; amp;,cüm

cognofcitur vera radix ^jhïCJEquatioA-';»: 4-^-v— OOo ad duas reliquas inveniendas adbiberi poterit.

C A P V T VI.

De nattira ^ conjiitutione (^yËquationum quatuor di~ menjiontm.fecundo amp; tertio termino car ent turn.

Vjus generis aequationes ad tres formas fequentes redu-cuntur:

* nbsp;nbsp;nbsp;* _J_„3_y__j54 33 o.

* nbsp;nbsp;nbsp;* —tigt; X—f X o.nbsp;a;quot;* * * —X O.

I Dropofitjo.

Pro natura amp; conftitutione prioris propofitionis formemus ex duabus x^-Jrbxx-irbbx-\'C^ X o amp; a;—^xohanesquatio-nem a:'* * * a; — ^ c^Xo. Suppofito verb majore quam b\

habebiteaeandem formamatqueprimapropofitio x‘**^ n^ x —X o, amp; per confequens erit ejufdem naturx amp; conftitu-tionis. Piat ergo comparatio, amp; ex collatione qnartorum rer-m'inorum habebitur e’ ¦— x hoe eft, e^X »’ bK unde co-gnofcimus, quando innotefcit vera radix b, asquationem handnbsp;x^ bxx bbx-\-n^ -P^’Xo fpedtareadinveftigationem triuninbsp;reliquarum radicum.

Prïterea, collatis ultimis terminis, £tp'*0Dbc'': undefequi-tur, c^asquari^ ; amp; , cognka vera radke^, sequationem hanc Pars II,nbsp;nbsp;nbsp;nbsp;Knbsp;nbsp;nbsp;nbsp;a;^ Hr

-ocr page 102-

74

De Natvra

hxx /

èx tl CO o ad tres reliquas inveftigandas

pofTe ufurpari.

^ ^rofojitio.

Pro fecunda propofitione fiat ex duabus x^-^-hxx-^-hbx-^-c^rxiO Sgt;i x—'bZDo haecsc^uatio** (;* a;— bc^ ZD o. Et,fi pona-

— b^

tur b'' major quam c’', habebit illa eandem formam atque fecunda propofitarum * * —n^x—p'^ CD o , amp; confequenter eruntnbsp;ejufdem naturx amp; conftitutionis. Fiat jam comparatio , amp; exnbsp;collatione quartorum terminorumhabebimus —é* CD—nbsp;hoceft,c^ ZO b^—Vndecognofcimus, inventa veraradicenbsp;hancaequationemx^ -\-bxx bbx-\-b^ —CD o, ad tres reli-quasradicesrefpicere. Porró, comparatisi'nterfe terminisulti-

mis,babebimus/ zob Vndefequitur, aequari ^; amp;,cogni-

taveraradice^, hancsquationem ^ GO o tres reliquas radices concernerc.

5 Tropojiüo.

Pro tertia propofitione fiat ex éai}a\x% x^ -^b x x-\-b b xc^zoo Sc Xb ZO o asquatio aquot;* * * —c'x b GO o,amp; habebit eandem

—b^

formam atque tertia propofitarum a'^** —A pquot;* GOo,ac per confequens erunt ejufdem naturae amp; conftitutionis. Fiat jamnbsp;comparatio, amp; ex collationequartorumterminorumhabebimusnbsp; CD »’jboccft, f’GOnbsp;nbsp;nbsp;nbsp;Vndeconftat, cognitavera

radice^, aequationemhanc x^ bxx bbx — nbsp;nbsp;nbsp; GO o ad

tres reliquas inveftigandas adhiberi pofte. Praeterea ex collatione

p4

ultimorumhabebiturp”*GO Vndefequitur,c’aequari^ ;8c.

OOO

cognita vera radioed,aequationem hanc a’ ^,va ^^a-ad tres reliquas quxrendas efle utilem.

Ca-

-ocr page 103-

IS

iE,Q_VATIONTM. Capvt VII.

me natura ^ conflitutione ci^Equationum quatuor d't-menjtonum,tertio quarto termino car ent turn.


Quationes hse ad fequentes tres formas reducuntur:

nbsp;nbsp;nbsp;/30O.

— /jc’** —/J^CD O.

;c‘* —O.

I Tropojitio.

Ad cognofcendam naturam amp; conftitutionem primaepropo-fitionis, fiat ex multipUcationeharum duarum x^-^cxx-\-bcx-^ ^igt;czo o ècx — ^GOo hasc squatio a;quot;* r a;’ * * — b^cjD o.

__y

Suppofita vero c majore quam b, habebit illaeandcm formant atque prima propofitio x^-\- Ix^nbsp;nbsp;nbsp;nbsp;—¦ pquot;* ZO o, acper confe-

quens erunt ejufdein nature amp; conftitutionis. Fiat igituradac-quatio, amp; comparando fecundos terminoshabebimus c — b 30 hoceft, c CO/ 6. Vndedifcimus ,cognitaveraradke^ , hancnbsp;squationem x^ b X Xblx-^ b^ bblZO o tribus reliquisnbsp; /nbsp;nbsp;nbsp;nbsp;-\-b b

inveftigandis infervire. Deinde, collatis ultimis terminis, babe-hitavp^ZOb^ c. undefequitur,c3equari|J ; amp;, cognita vera radices, banc sequationem ^ nbsp;nbsp;nbsp; ^ o ad tres

reliquas indagandas adbiberipofle.


X Tropojïtio.

Pro fecunda propofitione fiat exduabus x^-^c xx-^-bcx-^ b bcZD o amp;c Xbzoo h3ec2Equatio;c'' e x^ * * b^cZOO. Ec

—b

fupponendo ^ fuperare ipfamc, habebit illa eandem formam atque fecunda propofitio a;‘‘— /a;’**.—p'* CD o, amp; confequenter erunt ejufdem natura amp; conftitutionis. Fiacergoadsequatio, amp;nbsp;collatis fecundis terminorum habebimus—b czoh boe

K 2 nbsp;nbsp;nbsp;eft,

-ocr page 104-

^6 nbsp;nbsp;nbsp;DeNatvra

eft,c30 yl- VndedifcimuSjCOgnitaveiaradice^jXquationetn hanc x^ bxx-^-ybx b^ —nbsp;nbsp;nbsp;nbsp;oad tresreliquasinvefti-

~bl

gandas ufurpari poïle. Praeterea, comparando poftremos tertni-norumshabebimuspquot;* X b'^ c. Vndefequicur,c£Equan j amp;, co-

gnitaveraradice^,£Equationemhanc ^ nbsp;nbsp;nbsp;Xo tri

bus rehquis infervire.

3 Tro^ojïtïo.

'—bbcODoamp;x — ^Xo a:quatio hare x‘^ — cx^** ^’£'Xo

Pro tertiapropofitione formeturex duabus— cxxbcx-

¦b

amp; eritejufdem formae atque tertia propofitarutn x*—/at’

ƒ¦* X o , ac per confequens eandem habebunt naturam amp; confti-tutionem. Fiat ergo adaequatio y 8c ck collatione fecundoruna termmornm habebinaus l x c-^-b, hoe eft, cTO lb. Vndenbsp;conftat, cognita vera radice b, hanc a;quationemnbsp;x^ixx—blx bbl-^b^ CD o tribusreliquisinftrvire. Por- ^nbsp;nbsp;nbsp;nbsp;-^-bb

ro, comparando poftremos terminos,habebimuspquot;* x c, amp; per confequens c X ; adeoque, cognita vera radice^, poteritae-

quatioA:’xx—^ xo ad tres reliquas radices in-veftigandas adhiberi. ,

Non operae pretium duximus meminiflTe sequationum quatuor dimenfionum, inquibus fecundus amp; quartus terminusdefunt:nbsp;quia illas omnes reducuntur ad Quadrafas, ac idcirco earum na-tura amp; conftitutio eodera raodo habetur.

Ca*

-ocr page 105-

77

^CLVATIONVM.

c A p V T viir.

2)^' natura amp; conftitutione (:_/Equatwnum quatuor di-menJionum,fecundo termino carenthim.

7F. Quationes hx reducuntur ad feptem formas fequentcs:

jcquot;*^ — mmXX xfquot;quot;CO o. x‘'*^-\-mmxXX —CO o.nbsp;a;'* — mm xx—x —p'* CO o.nbsp;x^^ -\-mmxXX—p'* 00 o.

X^*-ATAT n^ AT-^-p'* CO o.

xquot;*^ -i-mmxx — »^A? p‘*COo. x*^-i~mmxx —nbsp;nbsp;nbsp;nbsp;A:-t“p‘*0O

I ^ropojïtio^

Ad cognofcendam naturam amp; conftitutionem prims propo-fitionis, fiat ex multiplicatione duarum a;’ ^ x xc c nbsp;nbsp;nbsp;O

amp; AC—^XoViaecaequatioA;'**—ccxx-^d^’x—b d^ZOo. qusean-

—bb -^bcc nbsp;nbsp;nbsp;*

dem habebit formam atqueprima propolitarum a?***—mmxx »^ X—p‘’Xo, ac perconfequenseruntcjufdemnamras amp; con-ftitutionis. Fiat ergo adsquatio, amp; excollatione tertiorum. ter-minorum habebimus mmZD cc bb-gt; hoe eff, c cZCi mmbb.nbsp;Deinde, comparando terminos quartos,ent ZD d^ -{¦ b c c, hoenbsp;eft, reffituendo valorem «-einventum, habebitur d^ ZOn^ b^nbsp;—Vndecomperimus, cognitaveraradice^, hanesqua-tionemx*q-^A:Af nbsp;nbsp;nbsp;nbsp;Xo tribus reliquis indagandis infervire.

—m b^

bmm^

Prsterea , conferendo inter fe terminos ultimos, habebimus p^X Vndcfequitur, ci’aequari^ ; amp;,inventaveraradioed,

hanc squationem x^ bxx-—mmx r Xoadtresreliquas

bb

qusrendas adhiberi pofiè.

2, Fro-'

-ocr page 106-

78

De Natvra

X Tropofitio.

Profecundafiatex multiplicationeAr’ ^arAr Ci'A’ ^’X9 per X—bzo o hïc asquatio x^* -^-ecxx eé^xégt; CO O.

b b nbsp;nbsp;nbsp;—ccb

Suppofito verócc majorequam^^, amp;l ccb majorequama!^, ha-bcbit illa candem formam cum lecunda propoluarum nbsp;nbsp;nbsp; mr»

XXX—CO o, ac per confequens eruntejufdem nature amp; conftitutionis. Fiat igitur ad^quatio, amp; ex comparatione tertio-rum terminorum habebimus mmCOccbh, hoe ch^ccCDmm bb.nbsp;Deinde, collatisquartis terminis ,ent—cb^-\-d^co—hoe eft,nbsp;reftituendo valorem cc inventum , habebitur do bmm -\-b^n^. Vnde difeimus, eognita vera radiee b , sequationemnbsp;x''-\-bxx mmx bmm02o, tribus reliquis inveftigandis infervire.

•\-bb -\-b^ nbsp;nbsp;nbsp;*

•—

Prxterea, comparando ultimos terminos,habebimusCDd'' b. undefequiturj^i’iEquari ; amp;, eognita vera radiee arquatio-

nemhanex^ bxx mmx ^-^ xoadtresreliquasindagan- bb

das pofle ufurpari.

3 Tropfitio.

Pro tertia, fiat cx duabus his x'^ bxx ccx d^ COoSc Xb ooo xlt;imnox'^^ ccxx-^d^x—d^bcoo. Et,fuppo{i-—bbnbsp;nbsp;nbsp;nbsp;gt;—ccb

tobb majore quam e e,amp; ccb majore quam lt;5?^,habebit ipfa candem formam atque tertia propofitio xquot;quot;*§tmxx-n^x—^'*000,ac pernbsp;confequens ejiifdem erunt naturae amp; conftitutionis. Vndefaéfanbsp;adaequatione , ex collatione tertioriim terminorum habebimusnbsp;—mmCD—^^ ee,hoc eft,ceOD^^—mm. Deinde,collatis quartisnbsp;terminis, habebimus — CO — ee^^-^f^,hoc eft,fubftituendonbsp;valorem cc inventum, eritlt;^* CO b^ bmm — undepatet, ftnbsp;eognita fit radix vera hane £Equationemx^ ^ArAr ^^Ar ^* 00 o

m^ -k-bm^

tri-


-ocr page 107-

iËQ^VATIONVM. nbsp;nbsp;nbsp;79

tribus reliquis inveftigandis infervire. Poftremo,coniparando ul-timosterminosjhabebimusp‘^ZDbd\zcproinded^zo^-^ i amp;,co-

gnitaveraradice^,poteritaequatiox'^ nbsp;nbsp;nbsp;bxx ^bx-{-^1 qqo

mm

ad reliquas tres inveftigandas ufurpari.

4 Tropfitio.

Pro quarta propofitarum formetnus ex duabus x^— b x x-\-ccx d^zoo8cx—booo hanc jequationema;^* r’^'ar.v lt;/'^—d^bcoo.

—bb —ccb

Etfuppofitoffrmajorequam^, acd^ majorequamre^, habebit tpfa eandem formatn atque quarta propofitio xquot;* * -t- mmxx n^xnbsp;'p* GO o, ac per confequens erunt cjufdem naturas amp; conftitu-tionis. Fiat ergo adsequatio, amp; comparando tertios terminosnbsp;habebimusmmZDcc—b h,\ioc eft, c cZOmm-\-hb. Deinde,con-ferendo quartos terminos, habebimus GO^si*—ccb, hoe eft,nbsp;reftituendo valorem c cinventum,erit^i’ JX5 b^-\-bmm-\-n^.\\i^^nbsp;difcimus, cognita vera radice ^,2quationem hanc x^ bxx mmx

-gt;tbb

4-^5 GO o tribus reliquis quasrendis infervire. Denique,coIIatis 4- bmmnbsp;ultimis terminis, erit^i’ bzDp^', amp; per confequens^’ 00 ^. unde,

cognita vera radice ^,h2c jcquatio nbsp;nbsp;nbsp;x x-\-m m x -i-T xo

•^bb

ad reliquas tres indagandas erit adhibenda.

5 Trofojitio.

Pro quintapropofitione, fiat ex duabus x^-\-bxxccx-^d^ZDo amp; X — bzo o hasc squatio xquot;^* — ccxxd^x-{-d^ bZDO. Et

hb -{-bcc

fuppofitobccmajorequamd^, habebit ipfa eandemformam atque quinta propofitarum x^* — mmxx-4-»’ x p‘^co o, ac per confequens ejufdem erunt naturx amp; conftitutionis. Fiat jam ad-«quatio,amp; comparaudo tertios terminos habebimus

hoe

-ocr page 108-

8o nbsp;nbsp;nbsp;DeNatvra

hoc eft, cc30»?»« — hb. Deinde, confercndo quartos terminos, habebimusK’oo^cc—d^-, ideoque,reftituendo valorem cc inven-tum , critis!* ZD b mmb^-n^. Vnde patet, cognita vera radi-cc ^,hancseqLiationem;e^ ^x xmmx—bmmzoo reliquis

•^bb

tribus quxrendis infervituram. Denique,comparatis ultimis ter-

/j4

minis,habebimus b öDp*- Vnde fcquitur, xquari ~ ; amp;,cognita vera radice b, hanc xquationem x^-{-bxxmmx—^ zOo

bb

ad tres reliquas inveftigandas pofte adhiberi.

6 Tropfitio.

Pro fextapropofitioneformemusex duabus x’ b xx ccx -—d^ ZO o SixbzO o hanc xquationem a:quot;* * -f- ccxxd^ x

—bb nbsp;nbsp;nbsp;—ccb

lt;si* ^CD o. amp; fupponendo c c majus quam bh, habebit ipfa eandemformamcumfextapropofitarum x‘^*-\-mmxxxnbsp;CD o, ac per confequens erit utraque ejufdem naturx amp; con-ftitutionis. Fiatergo adxquatio amp; per comparationcm fecundo-rum terminorum habebimus mmZOccbb^ hoe e^,ccZDmm-\-bb.nbsp;Deinde,collatis tertiisterminis,habebimus»^ ZO d^-^- ^cc, hoenbsp;eft, reftituendo valorem cc in ventum, entd^ ZObmm—nbsp;Vnde patet, data vera radice b, xquationem x^-\-bxx-\-mmx

—b b

ngt; GO o ad triumreliquaruminveftigattonem pofte ufurpari.

-\-bmm -f- b^

Poftremo, comparando ultimos terminos, crit^quot;^ GO d'^ b. unde fequitur,c/’xquari^ j amp;, cognita vera radice^, hanexquatio-

-{'bh


nQm. x^-\-b xx-\-mmx—r 00 o adreliquas tres quxrendas

efte adhibendam.

7 Pra~

-ocr page 109-

8i

iElt;5_VATI0NV

7 ‘Pro^ojitio.

Profeptima propofitarum fiat ex diiabusx^ ^-^.^' rrAr—d'^’Xio amp; KbZDohscsequatioa:*** -^ccxxd^x ^lt;/*CX)o.Etlup-

bb ¦—bcc

pofito bb majore quam cc, habebit ipfaeaiidetn formamatquc feptiraa propoficiox'^*mmxxngt;x-\-p‘^COo,8c per confe-quens ejufdem eruntnaturse amp; conftitutionis. Fiat ergo adjequa-tio,amp; comparando tertiosterminoshabebimus — mmzobbnbsp; e c, hoe eft, f e 3D ^ — mm. Deinde, collatis quartis terminis,erit n^zod^ bee, boe eft,reftituendo valorem c c inventum,nbsp;erit d* 03nbsp;nbsp;nbsp;nbsp;— b’^Jfbmm. unde conftat, cognita veva radice,^,

hane asquationem x^^b x x b b x—COoad reliquas tres

—mm

—bmm

inveftigandas utilem effe. Poftremo, eomparando ultimos ter-

ft 4

minosjhabebirnus/)'' oo bdd. unde difcimus,«^’ squari^~ ; amp;,eo-

gnitaveraradice6,hancsEquationemAr^ ^A;A'4-^E\-—^ 00 o

m^b

ad reliquas tres quserendas adhiberi poffe.

C A P V T IX.

natiira amp; conjlitutione zy^quattonüm quatmr dimenjionum, quarto termino carentium.

pT iE squationcs redueuntur oranes adfeptcra fequentes for--*¦ mulas:

a;** — Ix'^-^ mmxx^•p‘^ oo o. x^'^lx^mmxx*p^ZD o.nbsp;a;quot;*—Ix^mmxx*-p‘^ZD o.nbsp;AT** — lx^-\-mmxx*p'^ZD o.nbsp;xquot;quot;Ix^ -^-mmxX * p*ZOo.

x^-^lx^—^mmxx* -{-p‘'ZO o.

Ar'*'—Ix^—mm XX* -\-p'^^ a.

I Tro-

Pm II,

-ocr page 110-

De Nat

1 Tropofitio.

Adinveftigandam naturam amp; conftitutionem prima? propofi-tionis, formemusexduabus — cxx ddx bdd OD o 5c X-—^ 30 o xquationemhancxquot;*—cx^ ddxxquot;^—bb ddzoo j

•—b bc

habebitque ipfa eandem formam atque prima propofitio x^lx'^-gt;rmm XX*p^ZDo, 8c per confequens dux illae squationcsnbsp;cjufdem erunt naturae amp; conftitutionis. Fiatjam adaequatio, 8cnbsp;ex comparatione feciindorum terminorum habebimus IcO cb,nbsp;feu cZD ^ b. Deinde,comparando tertios terminos, erit mmconbsp;dd b e,Koc eft,reftituendo valorem cinventum,babebitur 0/ d 30nbsp;mmblbb. undeconftat,(icognofciturveraradixhancnbsp;aequationem ¦—Ixx mmx bmmCO o ad reliquas tres in-— b •—bl —bblnbsp;bb —b^

veftigandas infervire.

^ Tropojitio.

Pro fecunda propofitione formemus ex duabus x’ exx ddxbddj:)o 8c xbcoo hanc xquationemx* cx’ ddxx

•—b —b c

* — ddbbZDo. Suppofita verb craajore quam 8c bc majore quamdd, habebitilla eandem formam atquefecunda propofita-rumx'^ /x’—mmxx*—o, amp; per confequens ejufdemnbsp;crunt naturae amp; conftitutionis. Fiat ergo adaequatio, amp; ex colla-tione fecundorum terminorum habebimus/30 b, hoe eft,nbsp;cCO l b. Deinde,comparatistertiis terminis,erit — mm CO ddnbsp;bc, hoe eft, reftituendo valorem r-inventum, habebitur 30nbsp;bl b bmm. Vnde difcimus,cognita vera radice ^,hanc a?qua-tionem x^ lxx blx b blCD o ad reliquas tresquaerendasnbsp; b -^-bb b^

—bm^

pofte adhiberi.

Denique, comparando ultimos terminos, habebimus /gt;'* 30 hbdd. undefequitur, ddxc^zti^^^', amp;, cumcognofciturvera

radix

-ocr page 111-

^q_vationvm:. nbsp;nbsp;nbsp;83

radix^jliancasquationemA-^ ^ CD o tres reli-

^ nbsp;nbsp;nbsp;-j-

-mm


•quas radices concertiere.

3 T'ropojïtio.

Pro tertia propofitione,^iat ex duabus x^ cxx ddx-^lgt;ddcoo amp; Ar-—hxcsquatio x‘^ cx^ ddxx*bbddzcgt;o. Sup-

b —bc

pofitisautem b majorequamc, Sibc majorequam^i^, habebit Jpia eandem formatn atque tertia propofitio x'^Ix^mmx xquot;*^nbsp;^/’“'CD o, amp;perconfequense)ufdemeruntuatur£E amp; conftitu-tionis. Fiat jam adxquatio, amp; comparando fecundos terminosnbsp;babebimus—IZD c—^,hoceft,£-CD bl. Deinde, conferendonbsp;tertios ternainos, erit ¦— mmZD ddbc, hoe eft,tcftituendo valorem c inventum,habebitur ddzob b b lm m. Vnde difcimus,nbsp;cognita vera radice ^,hanc tequationem Ar’-f-^ at x-^b b x-\-bblCO o

—/ nbsp;nbsp;nbsp; bl b^

¦bm*

tribus reliquis infervire.

Poftremó, comparatis ultimis terminis, habebimus p'^cobbdd. underequitur,lt;;/lt;ixquari|-nbsp;nbsp;nbsp;nbsp;cognita vera radice Zgt;,hancéequa-

tiönem x^-{-bxx bbx-— / bl

—mm


-g pro tribus reliquis ufurpari.


4 Propofitio.

Pro quartapropofitionefiatex nbsp;nbsp;nbsp;x^ cxx ddx bddcoo

amp; a:^—bcoohxc tequatio nbsp;nbsp;nbsp;ca; ddxx*bbdd coo. Sup-

— b —bc

pofitis autem cmajorequam é, 8c dd majorequam bc, habebit 'pla eandem formam atque tertia propofitio x'^-^lx'^ mmxx*—nbsp;Pquot; 00 o, ac per confequens duae illae aequationes eandem habebuntnbsp;oaturam amp; conftitutionem. Fiat jam adaequatio, comparatisquenbsp;bïcundis terminis habebimus Ico c—b, hoe eft,c 00 / !gt;. Dein-

L z nbsp;nbsp;nbsp;de,

-ocr page 112-

84 nbsp;nbsp;nbsp;DeNatvra

de, conferendo rercios teriiiinos,habebimus m m ZOdd[?c,\-iOC eft, reftitaendo valoremcinventum, zntdd 'j:gt; mmb 1 bd.nbsp;unde conftat, cognita vera radice b, banc aequationetnnbsp;x^ lxx mmx bmmZOoiA tres rebquas adbiberi. *

-\-b nbsp;nbsp;nbsp;'\~bl -\-bbl

-\-bb nbsp;nbsp;nbsp; b^

Denique , comparando ukimos terminos, babebimusp'* CD undefequitur,i^^/2quari^^; amp;, cognita vera radice b,

banc sequationem x^-\-b x x-\-mm x r CO o ad reliquas tres

—J” I “f” b l -\-bb-

qusrendas effe utilcm..

5- Tro^ojitïo.

Pro quinta propofitione,fiat ex duabus,A:’—cxxddxbdd'X^o amp;; X'bZDo, bsec aequatiox'^—cx^ddxx^-\~bbddzDo.]Lx.

—b ’^b c

fupponendo bc tnajus quam dd, erit ipfa ejnfdem formrecum quinta propofitione x'^—/x’ w? x a; * -4-p'’C0.o, ac p er. con-fequcns. eandem babebunt naturam amp; conllitiitionem. Fiat jamnbsp;adsquatio, amp; comparatis fecundis terminis,babebimus 100 b c,nbsp;boe eft, f OO l'b. Deinde,ex comparatione tertiorum termino-rum,babebimus mmoo bcdd,hoc eft, reftituendo valoremnbsp;inventum c, erit dd 00 blbbmm. unde patet, cognita veranbsp;radice ^, banc squationem a-5Ixxblxbblooo^é. reli-

b -^bb bmm •^mm b^

qiias tres quxrendas adbiberi pofte.

Poftremó, comparandoultimosterminos,babebimus bbdd

COp^aeper confequenslt;iia!oo^j. unde, cognita vera radice^.

baecsequatio at’—Ixxblx-

quot; b -\-b b

-{-mm

veftigandis infcrvire poterit.


CO o pro tribus reliquis kï-


6 Prlt;r

-ocr page 113-

itO^VATIONVM.

6 ^ropofitio.

Pro fexta propofitarurtijfiat ex duabus x^-\-cxxcLcLxbdd'Xgt;o Scx — b 00 o hxcasquatio x*-{-cx^ddxx*-{-bbddöD o.

bb c

Supponendo autem c majorcm qviam b, habebii ipfa candem for-niam acque fexta propofitio, ac per eonfequcns ejufdem erunt na-tura amp; conftitutionis. Fiat ergo adsequatio, amp; comparando fe-cundosterminoshabebimus/oo c—^,hoc cft, eooZ-J-^. De inde,ex collatione terciorum terminorum,habcbimus mmoodd bc, boe eft,reftituendo valorem cinventum, erit ddzDm m—b lb b.nbsp;Vnde difcimus , cognita vera radice b, hanc ïquationem

mmx bmmzo o tresreliquas radicesrefpicese. 4-^nbsp;nbsp;nbsp;nbsp;J^-bbl

-\-bb

Poftremo, ex comparationeultimorum tertninorum, habebi-musbbddy^cper confequensddzo^^ adeoque, cognita

vera radice èjhïcaequatioA:^-|-/a: AT—mmx — ^ 00 o ad tres

-\-b bl -^bb

rcbquas inveftigandas erit adhibenda.

7 Tropqfitio..

Pro feptima propofitione, fiat ex duabtis, a;’ c at at — dd xbddZDo Sc XbzDOjhïC squatiox^ cx^—ddxx'^ bbdddDo.

b •—bc

Suppofita autem b majorequame, habebitipfaeandemformam aique feptima propofitarumAj'* — /at^ — »j«?a; at * /?'* 00 o , acnbsp;per confequens ejiifdem erunt naturae amp; conftitutionis. Fiat ergonbsp;adaequatio, amp; per comparationem (êcundorumtcrminoriim ha-bebirnus cbzo—/,hoc eft,c00 ^—l- Deinde, eonferendonbsp;tertios terfninos,habebimusmmZD dd bc, hoe eft, fubftitutonbsp;Valorccinvento, ernddco mmbb bl. unde difcimus, cognita vera radice^,hanc aequationemAT^ ^XA;—mmx—bmmzoo

—[ ^bl —bbi •^bb ^5

L j nbsp;nbsp;nbsp;tribus

-ocr page 114-

86 nbsp;nbsp;nbsp;D E N A T V R A

tribus reliquis infervire. Denique,comparandopoftremoster-

minosjhabebimusp'^ooé'iamp;is/isi; acpercon{equensis((a(oo j amp;,

cognitaveraradice^jhaecxquatioAr^ ^ATAT — mmx—^ 30 o ad tres reliquas erit referenda.

X.

natura amp; conflitutione i^yEquatiomm quatuor dimen/ionum, tertio terminocarentium.

Tgt; Educuntur autemhse jequationes ad feptem fequentes for-mulas:

«3 nbsp;nbsp;nbsp;—P^ OO o.

-p‘' co o.

-p*3D O.

* nbsp;nbsp;nbsp;—/’“’CO o.

x‘*— nbsp;nbsp;nbsp;a; p‘*3onbsp;nbsp;nbsp;nbsp;o.

x‘^-{.lx'^^ — nbsp;nbsp;nbsp;3Qnbsp;nbsp;nbsp;nbsp;o.

a;4 — /x’* — »^'gt; p'^00 o.

I Tropojitio.

Pro natura amp; conftitutione primae propofitionis, formemus, cx duabusA.’’ — cxxhcx-\- «af’ooo amp; A — ^C0o,hanc squa-tionetn*** — cx^ * d} Xbd^ ZDo y Öc habebit ipfa eandemnbsp;— bnbsp;nbsp;nbsp;nbsp;~\-bbc

formamatqiie prima propofitio AT'*—lx'^* n x—p‘*C0o, ac per confequens ejufdem erunt naturs amp; conftitutionis. Fiat ergonbsp;adxquatio, amp; ex comparatione fccundorum terminorumhabe-bimus/oo c ^jhoceft,c CO /—b. Deinde, conferendoquartos terminos,habebimus CO d^ bbc,hoe eft, reftituendo va-quot;nbsp;lorcminventume,erit^* CO — bbl b’^. Vndedifcimus,co-gnita vera radice b, hanc aequationem ar* —Ixxblx n^ZOO

-\-b bb -\-b^

—bbl

ad tres reliquas quserendas adhiberi poflê. Denique, comparando

uhi-


-ocr page 115-

jE,Q_VATIONVM. nbsp;nbsp;nbsp;87

ultimos tertninos,habebimusj!i'*00 bd^- undefequitur,!^^asqua-

ri^ ;amp;,cognitaveraradioed,hzcsequatio—ixx—00o

ad reliquas tres erit referenda.

^ Tropofitio.

Pro fecunda propofitione,fiat ex duabiis,A-^ CAr.v4-^cAr lt;5/^ooo

I. nbsp;nbsp;nbsp;\nbsp;nbsp;nbsp;nbsp;'nbsp;nbsp;nbsp;nbsp;A .nbsp;nbsp;nbsp;nbsp;1^.»»nbsp;nbsp;nbsp;nbsp;lgt;/_.nbsp;nbsp;nbsp;nbsp;t-gt;

f nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;¦

X-

bZDO,\\xcxc^üüox'^-{-cx'^ nbsp;nbsp;nbsp; d^x — ^OOo. Suppo

—b nbsp;nbsp;nbsp;—bbc

fitis au tem c majore quam b,amp;c b bc majore quam d^, habebit ipfa tandem formam atqiie fecunda proporitio.»:^4-/’A;5*'—ri^x-p*odo,nbsp;2C per confequens ejufdcm erunt naturse amp; conftitutionis. Fiatnbsp;ergo adaequatio, amp; per comparationem fecundorum termino-ï’nmhabebimus 5 IZO c—^,boceft,e x/ ^. Deinde,collatisnbsp;«jnartis terminis, babebimusd^bbc CO —nbsp;nbsp;nbsp;nbsp;gt;boe eft, fubfti-

tuendo valorem(rinventum ,erit00 bbl-\-b^—Vndepa-tetjcognita vera radice b, hanc Ecquationem x^^lxx-\-blx-^bhliao

-\-b -\rbb

tribus reliquisinfervire. Poftremb, per comparationem ultimo-rum terminorum, babebimusp^cobd^,3.c per confequens d^co^ .

cognita vera radice ^,h2C sequatio;e3 /a;' x blx-^ t CO o

-\-bb

ad tres reliquas inveftigandas erit utilis.

3 Trofofitio.

Protertia propofitione fiat ex duabus,Ar -^cx x-{~bcx-^d^cOo -bcoo^xc £EquatioA:‘* nbsp;nbsp;nbsp;nbsp;d^ x d^bCDO. Suppo-

—b nbsp;nbsp;nbsp;—bbc

fitis autem ^majore quam c, amp; majore quam habebit ipfa eandem formam atquetertiapropofuioA-quot;‘ /-^ *——p^'COo,nbsp;fe per confequens ejufdcm erunt naturae amp; conftitutionis. Fiatnbsp;itaque earum adaequatio, amp; per comparationem fecundorum ter-^inorumbabebimus/00 cb, hoe eft, r00 l b. Deinde, con-^erendo quartos terminos,babebimus d^-^bbcCD-— «^boc eft,

refti-

-ocr page 116-

g8 nbsp;nbsp;nbsp;DeNatvra

rcftituendo valorem cinvencum,eriti^’30^3 — tO. Vnde tlifcimus, cogniu vcra radice b-, liane xquationemnbsp;X ^nbsp;nbsp;nbsp;nbsp;l X X ~\~hlx-^ IbhzüozèLreliquas tres(juarrendasefl'e uti-

_|.ij -\-bb -\-b^

»3

lem. Denique, collatisultimis terminis,habebimusj!gt;'*00 «1’^, ac per confequensnbsp;nbsp;nbsp;nbsp;; amp; gt; cognita vera radice b, hxc aequatio

ix Xb Ix-i-Y 00 o ad tres reliquas eric referenda. ^bb

4 nbsp;nbsp;nbsp;Tro^ojitio.

Pro quarta propofitione fiat ex duabus x^ cxx-^-bex d^ZOQ dixbeo obasca:qaatiox‘‘ c x^'^-^d^xd^bzoo. Sup-

b nbsp;nbsp;nbsp;•—bbc

pofitis autem c majore quam^, majorequam bbc jhzhe-bit ipfaeandem formamatque quarta propofitarmn -^ n^xp^ZOo, ac per confequens erunt ejuldem naturae 8cnbsp;conftitutionis. Fiat ergo adsquatio, collatisquc fecundis terminis babebimus/oo cb, boceft, cZO b l. Deinde, comparan-do quartos terminos, babebimus n^zod^ — ^ é c, boe eft, refti-tuendo valorem cinvcntum,fietlt;Zgt; oonbsp;nbsp;nbsp;nbsp;Vndedifci-

mus, cognita vera radice^, bancaequationem

xx bbx n^ X o ad tres reliquas efle referendam. -rf”/nbsp;nbsp;nbsp;nbsp;bl -\-b^

—j- hbl

Denique, conferendo ultimos terminos,babebimus/)'* 33 d^ by ac per confequens lt;a!3 33 ^ . unde, cognita vera radice^, ha:c£E-

c^miiox^ bxXbbXZOO tribusreliquis inferviet.

*4- / nbsp;nbsp;nbsp;4“ ^ ^

5 nbsp;nbsp;nbsp;‘Pro^amp;Jitio.

Pro quinta propofitionc,fiatex duabus,—hex—dlzoo 8cX — ^XOjbaecSquatiox'* — c x^*^— ö!3x4-^^Z33oo. fuppo-

¦—b nbsp;nbsp;nbsp;-\-bbc

nendo autem bbc majus quara d^, habebit ipfa eandem formana

quinta

-ocr page 117-

JE Q_ V A T I o N V M. nbsp;nbsp;nbsp;89

atque quinta propofitio x‘*Jx^ * n^ x-^p‘' 30» ,ac percon-fequens erunt ejufdem naturae amp; conftitutionis. Fiat ergo ad-JEquado , comparandoque fecundos terminos habebimus /co e ^ , hoe eft, £¦ CO /— Deinde, ex collatione qiiartorum ter-minorum,habebimus»^CD —d\hoc eft,d’nbsp;iubftituto nempe valore c invento. Vndepatct,cüminnotcfcitnbsp;veraradix h, hanc aequationemar^—Ixx'— l^lxhhlcoo tri-

b -\~bh -4”

tgt;us reliquis infervirc.

Poftremö, ex collatione ultimorum terminorum, habebimus undefcquitur,d* aequari^ ; amp;, cognita vera radice^,

-r 000 ad tres reliquas in-

haüc srquationem x’ —I x x-—b l x-Veftigandas efle adhibendam.

lt;S Tropojitio.

Pro fextapropodtionc,fiat ex duabus,x’ c xx-\-bcx—o amp;x—bZDo , sequatio x**—cx'^ ^ xb OD o. Suppo-

¦— b nbsp;nbsp;nbsp;— bbc

fita autem c majore quam^', habebitipfaeandemformam atque fextapropofitarum xquot;* 4-/x’*— x f'^COo,ac per confequensnbsp;ejufdem erunt naturse amp; conftitutionis. Fiat ergo adsequatio,nbsp;comparandoque fecundos ternlinos habebimus l x c—é,hoc eft.nbsp;Deinde, ex collationequartorum terminorum, habebimusX ^^c, hoe eft, reftituendo valorem cinventum,nbsp;fietd^ODbbl —nbsp;nbsp;nbsp;nbsp;Vndepatet,cognita vera-radiceb, hanc

zquationemx^ lxx blx — o tribus reliquis infervire. b ¦ b b -^bbl

DeniquCj Conferendo ultimosterminos,habebimus zO bd\ Unde fequitur, d^ zquari ^nbsp;nbsp;nbsp;nbsp;cognita vera radice ^,hanc sequa-

L

•g' Xo ad reliquas tres efle referendam.

tionem x^ / x x b l x

^ -^bb

7 Pro-

IL

-ocr page 118-

90

De Natvra

7 ^ro^ojitio.

Profcptima propofinone,fiat ex Aü2ih\is,x^ cxx-\-bcxd}'X)0 amp; XbZDo, hscaquatiox^ cx^*•d^x bd^ CO o. Suppo-

—b nbsp;nbsp;nbsp;'—bbc

nendo autem b majorem quam c, habebit ipfa eandem formam at-que feptima propofitarum x*——n^x-{-p*COo, ac per confe-qucnsejufdem erunt naturas Sc conftitutionis. Fiat ergo adsqua-liOjComparandoque fecundos terminoshabebimus C'—bco —/, hoceft , cCOb — /. Deinde, excollatione quartorum termino-rum,habebimus OD is!* hoceft, reftitiiendo valoremcnbsp;inventum, fiet d^ COb^ -^bb l. unde fequitur, cognita veranbsp;radice b, hanc asquationemnbsp;nbsp;nbsp;nbsp;^xx-f-^ ^ a; — 00 o reliquis

tribus infervire.

Poftrcmó, comparatis ultimis terminis, habebimiisp'* CO d^ b. unde conftat, aquari^; amp;, cognita vera radice ^,£equationetn

liane x^ bxx b bx — C 00 o ad tres reliquas effe referendam. -/ -bl ^

C A P V T XI.

2)^ natura confiitutione cl/Ëqnationim quatiior di-merifionum, in quibus nullus terminus deejl.

R Educuntur hse tequationes omnes ad quindecim feqiientes formas:

x'*—Ix^-^mtnx X — nbsp;nbsp;nbsp;x-{-p^ CO o.

x'* — nbsp;nbsp;nbsp;-{~mmxx-{~n^x-\-p'^COO.

x'* — /x’ — mm XX'— »’x p^00o.

— /x5—¦ m m XX nbsp;nbsp;nbsp;X p'* CO O.

X4_j„/x’-f-zw mxx-—'«^x pquot;* 00 o. x'^-J-Zx^ — mmx X — w^x-J-p-^oo o.

x'*— Zx* -i-mmxxx—p* CO o.

XA 4- Ix^—mmx x-j-n^ x p* 00 ta

X^‘

-ocr page 119-

91

yE CLVATlONVM.

X—¦^‘‘00 o. X*Ix^—mmxxn''xo.nbsp;_j;4 — ix'immxx-^'ti^ X-—o.nbsp;x‘^ Ix^ m mXXxp‘^ ÜD o.nbsp;x^~\~lx^ mmxx-\-n^X'p'^ZD o.nbsp;x‘* /Ar5 — mmxxX-—p‘'ZD o.nbsp;x‘'-\-lx^mmxx-^nZ’X—ƒgt;“ oo o.

I Tropofitio.

Pro naturaamp; conftitutioneprima^propoiltionis, dignofcenda fiat cx duabushifce, x^cxx -\~ddx—ƒ* zo o amp;c x — ^30 o,nbsp;hïc ïquatiox‘* — cx^-\-ddxx¦—ƒ^ x nbsp;nbsp;nbsp;nbsp;* coo,qu2e eand^m

b ”4“ b c nbsp;nbsp;nbsp;—bdd

fiabebitformam atqueprima propofitarum x^~-' Ix^ mmx x— «ï Ar ^|4 330, ac per conrequens ejufdein erunt nacurre amp; confti-tutionis. Fiat ergo adïquatio, uiide comparando fecundos tcr-minos habebimus Izo c-^b, hoe eft, c 30 /—b. Deinde, confe-rendo tertios terminos, habebimus mmZO dd-{-bc, hoe eft,nbsp;reftituendo valorem cinventum,fiet(ii^ ZOmm-— hlHh ^ Turnnbsp;per eollationem quartorum terminorum habebimus n^'X)P-^bdd,nbsp;hoe eftjfubftitiiendo valoremddinventum,fiet/^ ZD n^ bbl—inbsp;bmmb^. Vnde conftat, eum innotefeitveraradixnbsp;nbsp;nbsp;nbsp;hanes-

^«ationemA;^—Ixx-k-mmx—ooo tribus reliquis infervire. J^b bbnbsp;nbsp;nbsp;nbsp;•—bbl

.— bl bm'^

Poftremó, donferendo ultimos terminos, habebimuspquot;^ ZD bf^. *^ndefequitur,/^xquari^ ¦, amp;, eognitaveraradice^ , hanere-

^UationemAT^—lxx-\~mmx—^ 30 o ad tres reliquas elTe re-

^ nbsp;nbsp;nbsp;-{-bb

Petendam.

z ^ropojitio.

Pro feeunda propofitione.fiat ex duabuSjAr^—cxxddx—P'Xgt;o Sc X—o, hsec scQUatio a;'*—cx^ddxx~px bf^Z)D o.

— b -^bc bdd

M 2 nbsp;nbsp;nbsp;Sup-

-ocr page 120-

92, nbsp;nbsp;nbsp;DeNatvra

Suppofitis autem b^c majorequam dd,amp;ihdd majorequam Jiabebit ipfa eandem formam atqucfecundapropofitarum x‘^—^nbsp;Ix^ mmx x n^ X /)‘*30 o, ac per confequens ejufdem eruntnbsp;nature amp; conftitutionis. Fiatergo adasquatio amp; per comparatio-netn fecundorum terminorum habebimus /oo «¦ hoe eft,nbsp;fCÓ/—b. Deinde, conferendo tertios terminos , habebimusnbsp;mmzobcdd, hoe eft, fubftituendo valorem c inventum, fietnbsp;dd:x:iblbbmm. Turn exeollationequartorumtermino-rum habebimus GO hdd—hoe eft,reftituendo valorem ddnbsp;inventum, fietƒ’ OD bblb^bmm—wh Vndepatet, eognitanbsp;vera radice^, hane aequationemx^ —lx x-^ mmx Zi:)0 tri-

^ bb

* nbsp;nbsp;nbsp;— bl -^-bMm

bbl

bus rcliquis infervire.

Denique, collatisultimisterminis, habebimusp-*cx) bp. unde fequitur, ƒ ^«quari^ ; Sc, eognitaveraradical, hanca’qua-

tionemA:^^—lx.x mmx — ^ CDoadtresreliquasinveftigan- b bb — bl

das pofte adhiberi.

3 ^ropojïtto. nbsp;nbsp;nbsp;*

Pro tertia propofitione fiat ex duabus^^—cxxddxpZDo, amp; X—éx o htee asquatio x^-cx^—ddx x—p x bp xo.

b bc bdd

Suppofitis autem dd majorequam amp; p mzjorcqa^m bdd, habebit ipfa eandem formam atque tertia propofitio —/x^ —nbsp;mmXX•—X -Jf-pZOO, ae per eonfequcns ejufdem erunt naturaenbsp;amp; eonftitutionis. Fiat ergo adïquatio, amp; per comparationemnbsp;feeundorum terminorumhabebimus ex/¦—b. Deinde, conferendo tertios terminos,habebimus — ddZD •mm,hoccü,nbsp;fubftituto valorecinvento, etit ddeo bl-^rmmbb. Tumexnbsp;comparatione quartorum terminorum habebimus bddf^COnbsp;—nbsp;nbsp;nbsp;nbsp;, hoe eft, reftituendo valorem d d inventum , fiet/* X

bbl^bmm—Vnde conftat, eognita vera radiec^, hanc

aequa-


-ocr page 121-

^q_vationvm. nbsp;nbsp;nbsp;93

ftiJuationeraAT^ — Ixx—blx — «’coo tribus rcliquis infervirci -J- b —mmbblnbsp;-\-bbbm^

Poftremo, comparatis ultimis terminis ,habebimusp‘' co ^ Qnde fequitur,Z* squari ^ ; amp;, cognita vera radice^, hancx-

^ OO o ad tres reliquas efle re-

quationem Merendam.

Ixxmmx--f- b —bl -3rbb

4 ^rofojïtio.

Pro quarta propofitione fiat ex duabus a?’—ca'a;—Mx—ƒ’coo amp;: Ar—30 ohaecxquatio at'* — cx^ddxxf^x~{-bf^XiO.

•— b nbsp;nbsp;nbsp;b c quot;quot;^bdd

Suppofitis autem lt;s? majore quam ^ c, amp; ^ ö! majore quam ƒ ’, babebit ipfa eandem formam atqucquarta propofitio x'*Ix^ —¦nbsp;mmxx n^x-^ p*02 o, ac per confequens cjufdem erunt natprsenbsp;amp; conftitutionis. Fiat ergo adsequatio, unde comparando fecun-dosterminoshabebimus cZD/h. Deinde, collatistertiisterminis , habebimusbcddzO‘mm,hoeeft,reftituendo valorem rinventum,fiet^;(^;^CO«2»24-^/—bb. Tumexcomparatio-nequartorum terminorum habebimus«’05 ^lt;5^öf—ƒ3, hoe eft,,

fubftituto valorelt;a!ö(invento,erit ƒ’ ÜD bmm-[~bblb^_«h

Vndeeonftat, cognita veraradiee^, hanc Ecquationem •3^^-—Ixxmmx—bmm ZO o tribus reliquis infervire.

4“^ ,— nbsp;nbsp;nbsp;—bbl

-i-bb -^b^

I^enique, comparatis ultimis terminis, habebimus,jpquot;* CO bp. undefequitur,/’aequari^ ; amp;, cognita vera radicel'.hanc xqua-

t'onem at’— ixx‘—mmx—r ZO o ad tres reliquasefie refe-

b -bl ^

bb

rendam.

M 3 nbsp;nbsp;nbsp;5 Pro-

-ocr page 122-

94

De Natvra

y Tropofitio.

Pro quinta propoGtione, formemusex duabiis, x'^-\-cxX‘{‘ d d X—ƒ ^ooo amp; X—^jhanc xc]ua.üoncm x‘^-i-ex^-{-ddxx—ƒ gt; x

¦igt;igt;c —^dd

CD O. SuppoGtis autem c majoreqiiam égt;, amp; dd majorc quam^c , habebitipfa eandem formam atque quinta propoGta-tnxxi xquot;'1x^m m XX •x-{-p'^ ZD o, ac per conlequensnbsp;cjufdemeruntnaturjE amp; conGitutionis. Fiat ergo adaE’quatio, unde comparando lecundos terminos, habebimus cZD l b. Deinde , collatis tcrtiis terminis habebimus mmZD dd — bc, hoenbsp;eft, Gibftituto valorc cinvento,erit 0!dzDmmblbb. Turn,exnbsp;collationequartorum terminorum, habebimus 00 ƒ ‘ -^-ddb,nbsp;hoe eft,refl;ituto valoreis^Éi! invento, erit/‘oow’-j-ww^—bbl—nbsp;Vnde patet, cognita vera radice b, hancrequacionemnbsp;x'^~{-lxx-{-mmxn^coo tribusreliquisinfervire.

,— bl ¦m^b bb -\-bbl

Denique, excomparationeultimorumterminorum, habebimus bpzDp‘^,^c per confequensƒ^CD^ .unde conftat,cognita vera

- r OOo ad tres

O

radice b, hanc sequationemx^ -{• lx x-i-mmx-

-i-b —bl — bb

reliquas efle referendam.

6 Trofofitio.

Pro fexta propoGtione Gat ex duabus x'^-{-cxx-\-ddx—f^ZDO amp; XbzQohxcJequatioa.'*’¦— bx^bcxx—hddx-^bpZDO-

-\-c nbsp;nbsp;nbsp;-{-ddnbsp;nbsp;nbsp;nbsp;•—

SuppoGtis autem £¦ majore quam b , amp; majore quami^i^,habe-bit ipfa eandem formam atque fexta propofitio arquot;' / x^—m mxx — «’.vH-p‘*00o ,acperconfeqnensejuldemeruntnaturte amp; con-ftitutionis. Fiat ergo adtequatio, amp; per comparationem fecun-dorum terminorum habebimus c 00 / ^' Deinde,collatis tertiisnbsp;terminis,habebiturr/^i—^cOO—mnty hoe eit, fubftituto valorem

in-

-ocr page 123-

^q^vationvm. nbsp;nbsp;nbsp;95

invento, erit Jlt;s!co bl-\-hbmm. Tuin,comparandoquartos tcrminós, liabcbitur 00 ƒ^ ^lt;a!lt;5?, hoe eft, feftituto valored dnbsp;invento, erit/^nbsp;nbsp;nbsp;nbsp;bmm —b^-bbl. Vndeconftat,cogni'

ta veraradiccb, hancaequationemx^-^lxx-^blx — nbsp;nbsp;nbsp;COo

-j- b -^bb •—b m m —mm -{-bbl

tribus reliquis infervire.

Denique, collatis ultimis terminis, habebimus^^ X bf^- unde fequitur,/^Kquari^ ; amp;, cognitaveraradice^, hancKquatio-

nem -{.lxx-{-blx—C xo ad tres reliquas efle refcrendam.

•{-b -{-bb nbsp;nbsp;nbsp;^

—mm

7 Tropojitio.

Pro feptima propofitione, fiat ex duabus, x'^ cxxddx —-pZOo amp; X—^Xo,hïc aequatio x'^-^-cx^ddxx-f^x-i-bf^20o.

—b —bc -i-bdd

Suppofitis autemcmajorequam nbsp;nbsp;nbsp;bddmajore.quamƒ ^,habe-

bit ipfa eandem formam atqvie feptima propofuio arquot;* -{-Ix^mmxx-{-n^x-{-pZD o, acperconfequens ejufdemeruntnature amp; conftitutionis. Fiat ergo adatquatio, unde comparandonbsp;fecundos terminos habebimus /x c — by hoe eft, cZOb-{-l.nbsp;Deinde,collatistertiisterminis,habebitur mmZD dd-^bc, hoenbsp;cft, reftituendo valorem c inventum yüetddco mm^— bbbl.nbsp;Turn ex comparationequartorurnterminorum habebimus Xnbsp;bddp, boe eft,fubftituto valoredd invento, erit/^zObm m—¦nbsp;bbL—«b Vndefequitur, cognita veraradice^, xquatio-nemhancAr3 ^;ex—mmx—bmmZDo reliquis tribusinfervire.nbsp; / b b

-^bl -\-bhl

Poftremo, conferendo ultimos terminos,habebimusp** X bf^, tinde fequitur,/’ïquari ~ j amp;,cognitavera radioed,hanc acqua-

tio-

-ocr page 124-

I!


De Natvra

tionemx^ XX—mmx — r 303 ad reliquas tres dTe refc-* -f/

l

rendam,

«

8 Tropofitio.

Pro oftava propofitionejfiat ex duabus,^;^—cxx-\-^x-^pzDo Scx — ^00o,h£EC£Equatiox*cx'*-{-ddxx-{-f^x—p ^xo.

1gt; h c nbsp;nbsp;nbsp;—bdd

Suppofito autcm bdd majore quam/^, habebit ipfa eandem for-matn atqiie oifl:ava propoficio — l x^-^m m x xx—j9‘‘Xo, ac per confequens ejufdem erunt naturae amp; conftitutionis. Fiatnbsp;ergo adaequatio, undecomparando fecundos terminoshabebi-mus IZD c by hoc eft , c X ^— b. Deinde,collatis tertiis termi-niSjhabcbitur mm ZO ddbc,\\oc eft,reftituendo valorem c in-ventum ,fietddzonbsp;nbsp;nbsp;nbsp;— bl bb.Tumexcollationequarto-

rum tcrminorum habebitur/’ ¦— bd dzon^, hoe eft, fubftituto vaIoreia!(a!invento,erit/^ X bmm’bbl—Vndecon-ftat, cognita veraradice^, hanc aequationem

Ixx mmx-\-bmmZOo tribusreliquis infervire. -^b' ~\-hb

—— y/quot;

Denique, comparatis ultimis terminis, habebimusp'* x bp, unde fequitur,ƒ ^ aequari ^ ; amp;, cognitaveraradice ^,hanc3equa-

tionemx^lxx-\-mmZO o ad tres reliquas efle refe-rendam.

9 Tropojhio.

Pro nonapropofitione,fiat ex duabusjjt^—cxxlt;Arddx-\‘pzoo Xb ZO o, haec xquatio a:”* — cx^ d^ x x-\-p x—p^ bzoo-

b ~\-b c nbsp;nbsp;nbsp;'—bdd

Suppofito veroƒ* majore quam bddy erit ipfa ejuldem formse cum

propolltionenonaa?-'— nbsp;nbsp;nbsp;/)‘‘X o, acpec

coii-

1*1


Pl



-ocr page 125-

^ Q_ V A T I o N V M. nbsp;nbsp;nbsp;97

confequens habebunt duae illae xquationes eandem.naturam amp; conftitutionem. Fiat ergoadaequatio, undecomparando fecun-dos terminos habebimus /x ^ £¦gt; hoe cft, c X /— h. Deinde,nbsp;comparatione tertiorum tcrminoriim, habebitur»?»? ODddnbsp; ^c,hoe eft,fubrogato valorecinventonbsp;nbsp;nbsp;nbsp;d d7£gt; f»mhb

•— bl. Turn collatis quartis terminis, fietzoPbddy hoe eft, fubftituto valore ddinvento, erit/^ X -f*nbsp;nbsp;nbsp;nbsp;quot;4“ b ^nbsp;nbsp;nbsp;nbsp;— bbl.

Vndeconftat, eognitaveraradioed, hancaequationem —lxx-\~mmX'-{-n^ Xo tribus reliquis inlèrvire.

’\‘ bb . ^bmm — bl b^

— bbl

Prasterea, comparatisultimisterminis, habebimus/i^X/gt;’. önde fequitur/^aEquari^ j amp;,cogmta veraradioed,hanexqua-

tionemx^lxx-\-mmx-d[-^^ Xoad tres reliquas efi'erefe--\-b J^bb ^

— bl

rendam.

ïo ‘Propojitio.

Pro decima propofitione fiat ex duabus hifce x'^ exx-^ddx PXo Sr X—too hscsequatiox^-\-cx'^-^ddxx f^xf^bZDO.

^bc —bd^

Suppofitis autem b raajore quam Cyamp;cbc majore quara dflt;/,nec non bdd majore quam ƒ ^, habebit ipfa eandem formam atque decimanbsp;propofitio x^Ix^mmxxxpzoo,ac per confequensnbsp;ejufdera erunt naturae amp; conftitutionis. Fiat ergo adaequatio,nbsp;comparatisque fecundis terminis habebimus r — bzD—/,hoc eft,nbsp;eZObl. Deinde, collatis tertiisterminis,habebiturlt;/d—beZOnbsp;—w?»,hoc eft,fubftituto valore c invento,erit ddtobbblmm.nbsp;Tum ex comparatione quartorum terminorum habebitur/^—bd}nbsp;CX) ngt;, hoe eft, reftituendo valorem dd inventum, fiet/^ ZD b^ —nbsp;bblbmm—n^. Vndeconftat, cognita veraradicebyhancas-

quationcmar’ ^a^a? ^^ x-\-b'gt; x o tribus reliquis inlervire. *—/nbsp;nbsp;nbsp;nbsp;—bl —bbl

—bmm —»»

De-

ƒ 7.

-ocr page 126-

r'!

I

|gt;

I’

p8 nbsp;nbsp;nbsp;DeNatvr

Denique, comparatis ukimis terminis , habebitur p‘^CD undc conftat,/ ^ tequari ^ ; amp;,cognita vera radice ^, hanc aequa-

x\oncrax'^bXXbbXOD o ad tres reliquas efTe refe--/ -bl ^

mm

ren dam.

II ^ropojïtio.

Proundecimapropofitionefiatexduabus x^-^cxx—ddx •—ƒ’Xgt;o amp; XbZDo bate tequatio x‘* c‘x‘*ddxx pxbpooo.

bbc ddb

Siippofuaautem b majorequam c*, habebitipfa eandemformam atque undecimapropofitiox'*Ix^mmxx n^x — p'*00o,nbsp;acperconfequens cjufdemerunt naturae amp; confticutionis. Faöanbsp;ergo adaequatione, ex comparatione fecundorum teriiiinorumnbsp;habebimus cb 00— /, hoe eft, c OO b —•/. Deinde,comparandonbsp;tertios terminos,habebimus m moodd-i- b c-,hoc elè, reftituendonbsp;valoremeinventum,cntddzomm-^bbbl. Turn,ex coila-tione quartorum terminorum , habebitur »’oo/^ d d b, hoe eft,nbsp;fubftituendo valorem dd inventum, fiet/^OOw* — mmb—Pnbsp;’^‘bbl. VndedifcimuSjCOgnita vera radice^, hanc aequationemnbsp;x^ b XXmmx-^n^ 00 oreliquistribusinfervire.

— / nbsp;nbsp;nbsp;—bb -\-bhl

•^bl nbsp;nbsp;nbsp;'—mmb

Poftremó , collatis ultimis terminis , habebimus b undefequitur,/^ aequari'^ j amp; ,cognita vera radice hanc ae-

quationem x'^-\-bx x—m mx-j-^-r oOo ad reliquas tres efle re-— / —bb ^

bl

ferendam.

iz ^ropojïtio.

Pro duodecimapropofitione,fiat ex duabus, nbsp;nbsp;nbsp;f ara: ddx

4ƒ300o amp; ar—^Xo,h2C lt;lic^^Üox‘^-\-cx^-{-ddxx-\~f^x—pb'Xiogt;

—b —bc —bdd

SuppOquot;

-ocr page 127-

iBCLVATIONVM. nbsp;nbsp;nbsp;99

Suppofitis autem c majore quaint, Sc ddmajorcqiumigt;c, nee non igt;dd majore qiiam, habebit ipfa eandem formam atquenbsp;duodecima propoliiioxquot;*nbsp;nbsp;nbsp;nbsp;x—^i‘‘pDo,ac

perconfeqtiens eruntejufdem natura: amp; conftitutionis. Fiat ergo adaquatio,undeconferendo fecimdos tcrminoshabebimvis/oo cnbsp;b , hoe eit , e DDnbsp;nbsp;nbsp;nbsp;Deinde, collatis tertiis terminis,

habebitur cO dd_h ^-.hoc eft.fubftituendo valorem c inven-

tum, ent ddzDmw b b h l. T um comparando quartos termi-noshabebimus— bddzO‘— nbsp;nbsp;nbsp;,hoeelt, fubftitiitovalorcdd

invento, erit/‘ CD bmm bbl b^‘—«*. Vnde difeimus, eo-gnita vera radice b, hanc aquationem x^ b x x b bx b^ ZDO

/ nbsp;nbsp;nbsp;-\-bl bbl

mm bm^

lt;—»*

tribus relic|uis infervire.

Denique,comparatispoftremis terminis,habebimus bf^ ZD p*, ac perconfequens/’co^ . undc,eognita veraradiee^, harere-

quatioar^ -{^bxx-^bbx-j-^ 30o ad tresreliquaserit referenda.

4-/ bl ^

13 ^ropojitio.

Prodceimatertiapropofitione,fiatex duabus, x^ cxx-^ ddx-^-p zoo amp; ar—^XO,haecaïquationbsp;nbsp;nbsp;nbsp;x

b •bc '—bdd '^f^bzoo. Suppofitis autem c majore qtiana b, Sedd majorenbsp;*luamiifj nee nonƒ^ majore c^alm b d d, habebit ipfa eandem for-^^m atquedeeimatertia propofitio x‘*lx^mmxx -^n'‘xnbsp;‘7'/’^ CD o, ae per eonfequens ejufdem erunt riaturat amp; eonflitu-^onis. Fiat ergo adxquatio, collatisque feeundis terminis,habe-bimus/xc —hoceft, e COl b. Deinde,comparando tertiosnbsp;terminos, habebimusmm zoddbc, hoe eft,reftituto valorecnbsp;'^'^'j^nto,c.ntddzo mmbbbl. Tum,comparatisquartister-*’^inis, habebimus—bdd, hoe eft,fubftituto valorein-Vento, erit/^QQ «nbsp;nbsp;nbsp;nbsp;—hmm. Vndeconftat, cogniia

N 2 nbsp;nbsp;nbsp;vera

-ocr page 128-

loo nbsp;nbsp;nbsp;De Natvra

vera

radice by hancsquationem x^-{-bxxhbx-\-b^ COO

/ nbsp;nbsp;nbsp;—bi -^bbl

— bm

reliquis tribus infervire.

Poftremo, ex collationeultimorumterminorum, habebimus bf^ZOP'*’ undefequitur,/^asquariC j amp;,cognita vera radice

-bn^

Poftremo, ex collationeultimorumterminorum, ha bf^ZOp'*’ undefequitur,/^asquari^ j8c,cognitavera_____

tres

hancacquationemAr’—bbx-^^-r 00 o adreliquas / —bl

efte referendam.

14 Tropojitto.

Pro decima quarta propofitione formemus ex duabus Hifce* x^-\-cxx-i-ddx-{-Po:gt;o 8c Xbzo o hanc «equationemnbsp;x*-{-cx^-\-ddxx ƒ^Xf^bojo. Suppofitisautemcmajorcnbsp;— bbcnbsp;nbsp;nbsp;nbsp;—bdd

quam^, amp; majors quamlt;s!ii, nee non ^i^4majorequam/^y habebit ipfa eandem formam atque decima quarta propoGtionbsp;x‘^-^lx^mmXXx—p'* CDo,acperconfequcnsejufdemnbsp;erunt naturae amp; conftitutionis. Fiat ergo adaequatio , unde exnbsp;collatione fecundorum terminorum habebimus IZDcby hocnbsp;eft, cOO/ ^- Deinde, comparatistertiis terminis, habebimrnbsp;d d—b czof» my hoe eft,fübftituto valore c invento,erit d dzonbsp;b b b l—m »*. Turn collatis quartis terminis habebimr ƒ ^—b d dnbsp;CO,— »^hoc eft, fubftituto valore 44 inven to, erit/^co b^ bblnbsp;^bmm —Vndedifcimus, cognita vera radice by hanc ae-quationem x^ b x x b b x b'zoo tribus reliquis infervire,.

bl —^bbl —m^ ~bm^

Denique,. excomparationepoftreraorumterminorum, habebimus f* CD ƒ * b. unde fequitur, cognita vera radice ^,hanc squa-

tïonsmx^-^xx bbx-^-^- X o ad tres reliquas eflè referendam.

/ bl ^ nbsp;nbsp;nbsp;^

—m'


rj FrS“

-ocr page 129-

101

iEQ_VATIONVM,

15- Tropojitio.

Pro decima quinta amp; ultima propofitione , fiat ex duabus, —ddx f^ CD o 8c xIco o, hxcaequationbsp;—ddxx-i- f^xbPZD o. Suppofita verb c majorenbsp;•— bb c -\~bdd

quam^, habebitipfa eandemformam atque decima quinta pro-pofitio x* lx^‘— mmxx nquot;^ Xp* ZD o, ac per confequens cjufdem erunt naturae amp; conftitutionis. Fiat ergo adïequatiojnbsp;conferendoque fecundos terminos habebimus ICD cb, hoe eft,nbsp;czo l lgt;. Deinde, ex comparatione tertiorum terminorum, ha-tgt;ebimus mmZD dd b c, hoe eft, fubftituendo valorem c inven-tum, fietddDDnbsp;nbsp;nbsp;nbsp;—bbbl. Tumcollatis quartis terminis,

habebitur ^f'^-^bdd,hoc eft, fubftituto valorem//^inven to, crity*^ ZDb^-\-bbl-{-n}bmm. Vnde difcimus,cognita vera ra-b, bane sequationem x^-\-bxx-{-hbx-^b^ CD o tribus re-

b l nbsp;nbsp;nbsp;b b l

—mm

bm^

liquis infervire;

Poftremó, collatisultimisterminis, habebimusp‘*c)0/'^ac per confequens ƒ 5 00 j . unde fequitur, cognita veraradice^,

hancaequationemAT^ ^-’f'^' ^^-^ T 00 o ad tresreliquas

/ ‘

— mm

cfleteferendam.

OBSERVANDA

I’ quot;Nj nbsp;nbsp;nbsp;nos in omnibus prsecedentibusadaequationi-

bus fupponere aequationes comparatas inter fc habuiflë Zque multas radices , aut veras, autfalfas, aut imaginarias. Et adnbsp;dignofcendas imaginarias a reliquis,infcrviet Traétatus Diori-fticus, quem fubjungere animus eft.

Qtrodfidiligenter perpendantur ea, qus prscedunt, pa-

N 3 nbsp;nbsp;nbsp;tebit.

-ocr page 130-

loz nbsp;nbsp;nbsp;De Natvra

tebit, mutatis fignis terminorumlocorum parium,ut iquot;*', 4'', amp;c. non mutatis fignis reliquorutn, ( coinprehendendo fub termino-rum numero etiam locos vacantes: ) lecundum terminum Temper asquari fumm$ radicum sequationis, affcciarum ctimfuisfi-gais amp;—; tertiumveró, fummseproductorum earundem radicum, cumfinguIsE binjein fe invicem ducuntur; amp;quartum,nbsp;fummae produdorum mulciplicationis , fadtk ex fmgulis ternis,nbsp;atque fic deinceps.

Vnde fequitur, deficiënte fecundo termino, ipfam falfam fum-mamvè faliarum radicum aequari ipfi vers vel verarumfummse ;

deficiënte tertio termino, produCtam velfummam produóto-rum ex billis, perfignum -H vel — deiignacorum, squari fum-ms produdtorum vel ei,quod ex reliquis binis producitur ac cum contrario figno afficitur, amp; fic de csteris.

Primum Exemplam. Fiat ex multiplicatione x—^ 00 g per af cOOo base squatio xxbxb cZDo. Qaare mutatis iignis

c

fecundi termini ac retento figno tertii, babebimusars ^s—¦

¦—c

beCOo. Vndeapparet, b — ceflefummam radicis vers bdc fall* —c; 8c bc efleproduótum ex multiplicatione falls — cnbsp;per veramq-^.

SecHtidum Exemplum^'viX deinde alia squatio xxbx-\-bc'X)0,

'—c

ex multiplicatione x — ^00 o per x — c ooo. Qtiare mutatis fignis fecundi termini,retento figno tertiijhabebiturxs ^Ar i’cXo.

c

Vndeapparet, c eflefummam duarumverarumradicum, amp; ^ c eflc produélum ex earum multiplicatione.

EertiumExemplum. Fiat ex continua multiplicatione trium radicum X bzD o, X — cOO o, amp; x fzo o squatiofequens: x’ — bxx bex bef 00 o. Quarcmutatis fignisterminorumnbsp;— cnbsp;nbsp;nbsp;nbsp;•bf

ƒ —

loco pari pofitorum, relinquendo figna reliquorum, habebimus bx x bexbef ZOO. Vnde apparet, fecundum tenniquot;nbsp;•hc —bf

-f .

nutn

-ocr page 131-

iECLVATIONVM. nbsp;nbsp;nbsp;lOJ

num b -f-1 —f effe fummam verarum radicum 4 nbsp;nbsp;nbsp;fal-

fx—ƒ; amp; tertium terminum hc—bfcf efle fummam trium produótorum ^£', — ^amp;—«¦ƒgt; prout lingulae binae radicesnbsp;in fe inviccm ducuntur; atquartumterminum — bef elfepro-duéium multiplicationis trium radicum ^, £',amp;—f. Patetnbsp;quoque, deficiënte fecundo termino , falfam ƒ arquari fummaenbsp;duarum verarum nbsp;nbsp;nbsp;nbsp;amp;, deficiënte tertio termino, pro-

dufta multiplicationis — bfSicf figno — afFeaa,*quari pro-dufto ^ r, figno affedto.

Quartum Exernplum.Vormtmxxs a?quationem ex continua mul-tjplicationetrium a;—b ZDo,x—cOO o,amp;x—dZDo, quaefit — bxx-^-bcxbcdZDo. Etmutatisfignislocorumparium,

¦ -f-dè * d -^dc ¦

retentis fignis reliquorum, habebimus x^ bxx dex bed.

c nbsp;nbsp;nbsp;b d

d ^ ^ c

Vnde perfpicimus,fecundumterminum b c d efie fum-mam radicum b,-\- c ,amp;c ‘d -, amp; tertium terminum d c d b -^-bc efle fummam produöorum ex fingulis binis radicibus in fienbsp;invicem dudis ; at quartum terminum bdc elfe produdèumnbsp;multiplicationis omnium trium radicum.

Quintum ExemflHm?t\zx. ex multiplicatione quatuor x—^OOo, X — cCDO,a; — dooo, amp; x ƒ CD o fequens sequationbsp;ac4,—,bx^ -df-b c X X'—bedxbcdfCD o. Vnde mutatis fignisnbsp;c —^bdnbsp;nbsp;nbsp;nbsp;quot;dr ^nbsp;nbsp;nbsp;nbsp;*

—d quot;^cd b df

ƒ

—cf

termmorum, locis paribus conftitutorum, retentis fignis relt-quorum, habebimus Ar** ^ b c x x nbsp;nbsp;nbsp;bed x^—b c df300.

•^c nbsp;nbsp;nbsp;-\-bdnbsp;nbsp;nbsp;nbsp;— bef

-{-d -^cd —bdf ~~f —bf —cdf

— nbsp;nbsp;nbsp;cf

— nbsp;nbsp;nbsp;df

Atque apparet, -^b c d —ƒ efle lummam quatuor radicum

squa-

-ocr page 132-

104 nbsp;nbsp;nbsp;D e N a t V r a

squationis; amp; tertiumterminumefle fummam produdorum et lingulis binis radicibus in feinvicem duftis; atquarmm termi-numefle fummamproduAorum exlingulis ternisradicibus; acnbsp;denique ultimum terminum efle produftum earundem quatuornbsp;radicum—ƒ, infeinvicemdudarum. PateCnbsp;quoque, deficiënte fecundotermino,falfam radicem—/aequarinbsp;fummx trium verarumnbsp;nbsp;nbsp;nbsp;Et, deficiënte tertio

termino , fummam produéiorumex binis, per — defignatorum, zquari reliqua: fummse produftorum ex binis, cumfigno af-feétorum. Non fecus fe res habet cum defecerit quartus.

Sextum ultimum exm/)/«»*.Fingamus quoque ex multiplica-* tione continua quatuor radicum xb GOo,a: —x;ZDo,x—lt;^000,nbsp;amp;tx—^/ooo hanc exurgere sequationem

-d

¦ƒ

—^ c d

4-bf

corum imparium, retentis reliquis, habébimus x^-^bx^-^bcxx-{-bcdxbedf. Atque apparet, fecun-•^bd -irbef

-^-bdf •\“cdf

x*bx^-i-bexxbcdx-\-bcdfo!:)o. Etmutatisfignis lo-— c -^bd —bef bdfnbsp;—xdf

«•

bf

•^cd

•ircf df

ƒ

dum terminum b nbsp;nbsp;nbsp;cfle fummam quatuor radicum ; tertium terminum bnbsp;nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp;eflè

fummam produdorum multiplicationis exfingulisbinis; quar-tum -{-bed -{-bef-{^bdf-^edf efle fummam produdtorum multiplicationis ex fingulis ternis; ac denique cflèpro-dueSum earundem quatuor radicum ^c, j amp; ƒ jnbsp;’fe invicem duólarutn.

Ca*

-ocr page 133-

105

A T I o N V M.

C A P V T XII.

Regiila pro invemendïs reliqtiis lt;^._yRi.qtiaüonis radïcihis, tind falfanm data,

Portetmutare fignaterminorum locoriim pariumsequatio-nis propolitï, ita ut falfae radices evadant verse, amp; vers fal-fe. Transforniatahoc padosequatioiie, fiippoGtaqueradice da-tïiprovcra, invcniatur sequacio, reliquis radicibus inveniendis miervienSjficutifupradócuimus. Atqueinsequatione ficinveii-tanautcntur fignaterminorimi locarumpariiim, habebimusquenbsp;^^quationem requifito fatisfacientem.

Exempli gratis EftosEquationisx5 4./a;ar — mmx — CO o

una ex fallis radicibus data, quse fit b, atque mutatis fignis tcrmi-norm-nlocorumparium,habebimusx5—/xa:—mmx oco. Supponatur jam radix falfa^hujussequationis efl'evera, atque utnbsp;habeatur sequatio, reliquis duabus radicibus inferviens, confula-tur Capitis V. Propquot;“ 2“^“; amp; elicieatur inde hse duse sequationcs

/x ^^00 oamp;XXCO o.

-{~b -\-bl nbsp;nbsp;nbsp;~\~l

mm

riumj liabebitnus XX —/x é^CO o amp;xx —^x 7- 00 o

Qiiocirca mutatis utriufque aequationis fignis locorum pans

T

¦mm

quarum quselibet qusefito fatisfaciet,

C A P V T XIII.

Ad tollendtm feemdumtermimm lt;:_/^quationum clvadratarvm.

X X /.V — »?oo o. Sit t:—i/oox,amp; habebimus nbsp;nbsp;nbsp;^//cd o.

'—mm '//OOo


Arx —/x —?»?»Xo. Sif^ ‘ nbsp;nbsp;nbsp;teritque^ —

•i/——^//xo.

II.

-ocr page 134- -ocr page 135-

^ ^ ^ ^

» -1^ nbsp;nbsp;nbsp;'«.P-I^C^nbsp;nbsp;nbsp;nbsp;1^-1- -!* •nbsp;nbsp;nbsp;nbsp;“I--1 nbsp;nbsp;nbsp;nbsp;fc-p -1^ A^ itA-l^-l^^

1 ! { I 1 1 1 ) 1 1

I 1, '' i'' t

' «V

^s iSs ^’8 #f r'f

J I J J J 1 . J I

«4

o

gt; 6 quot;a

t


-ocr page 136- -ocr page 137-

¦ ‘5!0?j’g; 'oCC^dX^u-\-xX ucui-—^^ x] v«

J-

-

•o0Ci««;/^r ï««/f— nbsp;nbsp;nbsp;i«lt;

--5; {/f H-'s:?//f-—^ ^-xant

x^uX X m ue-{-ix j^'X


gt;0^3

gt;3nb3iJ3'i

-x.u

iJ S

•KAN

i«/^—

•o0Ci««//*r—• t««/v—

¦7 nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;7 S.

^ nbsp;nbsp;nbsp;^ U ¦

f,d

{«/tH- iU —

• nbsp;nbsp;nbsp;o^z^tajf rnbsp;nbsp;nbsp;nbsp;— T««

t/ H s/ ^ nbsp;nbsp;nbsp;// f—

.d-

t«/? nbsp;nbsp;nbsp;{«

• nbsp;nbsp;nbsp;CCC/ÜJJ T*«/ ^ ï«lt; nbsp;¦^t/

•6oi

0^3 ¦oa:^d—x^u xxmtu—[.r;—^..v

f‘.vCC/r—/f

¦oCCj-

I -\-XXUtM-^^Xl-

[‘A-CCi Z^j

I X V A “ö


-ocr page 138-

I to nbsp;nbsp;nbsp;DeNatvra

Vndecolligcrelicet,omnesfuppofitiones , qu* adtollendutn fecuiiduiTi tcrminum adhibcmur, necedario exhibere jequatio-nemrealem, modb realcs radices adhienntinzquacionepropo-fita; amp; li nulls in his fuerint, idindicioeflè , nullas quoque eflenbsp;imaginarias in squatione propolua. Nam, exempli gratia, fifitnbsp;sequatio x*Ix^—.mmxx rr’Jr00 o; pateradix eftnbsp;realis, x ncceffariodeberesqualis eflei/, vclmajor, velminor.nbsp;Si squalisfuerit i /, ultimus terminus squationis transformatsnbsp;deficere debet ; (i major fuerit quam i /, squatio transformatanbsp;denominataaradicet:eritrealis; fidenique minor tuerit; transformata squatio a radicej denominata itidem realis crit.

Quod li fecundus terminus squationis propofits afficiturfi-gno -}-,ut,exempli gratia,11 fit x*-\-lx'^—mmx x-\-n^x—/gt;'*03o : patetjfi adlueritradixaliqua realis,luppofitionem hancz.—|/0Oa:nbsp;femper ellc neceflario realem ac denotare aliquam quantitatem;nbsp;adeoque transformatam squationem admittere quoque aliquantnbsp;radicem.

Deinde conftat, radices veras squationum a radicej denomi-natarum efle falfas squationum a radice z denominatarum; amp; contra, radices veras squationum a radice denominatarum elTenbsp;falfas squationum a radice^ denominatarum.

C A P V T XIV.

Contmens modum tollendi penultimum terminum c^yEquatiomm^fecmdo termino carent'mm.

T) Ro CMbicis. Supponatur ultfinus terminus divifus per incogni-tamquantitatem R^efiesqualis radici squationis propolits, amp; ficsequatiotransformetur, inquademum penultimus dcficietnbsp;terminus.

Pro Quadrato-qmdratis. Supponatur ultimus terminus divifus per incognitam quantitatem elTe sequalis radici ^quationisnbsp;propolitse , amp; turn rurfus transformata tequatione penultimusnbsp;terminus deficiet.

Pro aequationibusquinque dimenfionum fupponatur ultimus terminus divifus per incognitam quantitatem Rquot;* effe tequalis radici atquationis propofitte, amp; lie in infinitum , tranfmutatis deinde squationibus, uti didum eft.

Sed

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^Q_VAriONVM. nbsp;nbsp;nbsp;Ill

Sed pro sequationibus quatuor dimenfionumcommodius eft, fupponere quadramm uhimi termini divifum per incogniiaranbsp;quantitatem Refle sequaleradici incognito, atque itatransfor-mare xquationem.

Exemflttm Cnbicurum. Proponatur * mmx—»’cOo.Efto

^ CD a: , amp; , transformata aequatione, habebitur

'—^00 o. Hincmukiplicatis omnibus per

OOo, adeoquedivifis per»5,fietM* —R^ZDo, boe eft, per tranfpofitionem, habebitur — mmR*^ — OOo.nbsp;*quatio cubica, carens penulcimo termino, amp; in qua cum datur

iï‘exfuppofitionehabeturA'00 V •

Aliud Exemplam. Proponatur .v^* — mmx—00 o. Efto

00 X, fietque ^— b’ X o, hoe eft, R'^ -{-mmR**

-~n'^ CO o. aequatio cubica , in qua penultimus terminus deficit, amp; in qua cum datur , ex fupra pofita ftippofitione habe-tur Ar.

Tertmm Exemplfim. Proponatur at^* ¦—w^^^Ar-t-^’coo. Efto ^ X AC, eritque,transformataxquatione, ^nbsp;nbsp;nbsp;nbsp;Xo,

bgeeft, mmR‘^^ -\ryfi COo. xquatio cubica, carens penul-ftmo termino , amp; in qua cum datur R^ ex ftippofitione id habetur quod requiritur.

P'


Exemplum jQ^adrato-^uadratamm. Proponatur a;^*—mmxx H-«*ar—CD o. Efto ^ X AT, amp;, transformatasquaüoncfiet.

'K‘gt;' nbsp;nbsp;nbsp;—p‘'Xo. Hoe eft, multiplicatis omnibus

pcr.S4^ habebiraus p® — mm p‘^ nbsp;nbsp;nbsp;-\-n^ pp R'^ ^—p^ R‘' CO o, ac

pi^oinde divifis perp'*, habebitur .^4—m nbsp;nbsp;nbsp;—p^'ooo.

^^tiatio quatuor dimenfionum, carens penultimo termino.

^^^^plumfecundum. Proponatur at'**—n^x-\-p^cOo.

^upponendo^00Ar,transformeturxquatio,fietquc ~ fieftnbsp;nbsp;nbsp;nbsp;in*qua penultimus teiraiims de-

Exgquot;.-


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IIX nbsp;nbsp;nbsp;De N A T V R A

Exerfjfhm tertmm.Vïo'pondX'ü'c * — mmx x — n'^x-^p‘^Z£gt; o. Suppofita ATX)^ jXquatio transformata eritnbsp;H-p'^ 03 o, carcns pcnultimo termino.

Exempkm quartum. Proponatur a;quot;* **—w m x x n^ x p^CDo. Suppofito ^00ar,erit transformata xquatio^‘’ ^ E^mmR’-*nbsp; p‘^0DO, pcnultimo termino deftituta.nbsp;nbsp;nbsp;nbsp;«

Exemplum ^umtum. Proponatur nbsp;nbsp;nbsp;m x xn''x—p'^ooo.

?P

Etfuppofito^OOarjGBquatio transformata eriti2‘*H-^^i?’—mmK^

* nbsp;nbsp;nbsp;—p‘^ 00 O, carcns penultimo termino.

Exemplum ^extum. Proponatur arquot;* * — mmx x~n} ar—p‘‘xo*

Etfuppofito^OOar, erit ^quatio transformata

* _33 o, qu2 deftituitur penultimo termino.

Exemplumfeptimum. Proponatur a,quot;*^-k-mmxx -j. ti^xp^ZOo, Suppofito ^00 X, transformata tequatio eriti?'*—-nbsp;nbsp;nbsp;nbsp;—mmR‘'

PP

Ir

* —ƒ,4 33 o, carcns penultimo termino.

Exquibus manifeftum cft, ex omnibus sEquationibusaufewi pofl'e penultimumterminum, quandoquidem iuperiüsoftenfumnbsp;cft, ex omni aequatione tolli pofl'e fecundum, ac modó jam eft de-monftratum, quopado exsequationibus, fccundo termino ca-rentibus, penukimus terminus auferatur. ld quod annotafl'e opera; pretium duximus,cum Vieta,poftquam Capite 1“°nbsp;iionum Emendatione fecundum terminum cujufqüe atquationisnbsp;tollere docuit, versus finem ejufdem Capitis affirmet, poflenbsp;etiam aliquando alios auferri sequationisterminos, atqueexhacnbsp;Koftra quideoi methodo conftet, quomodo femperpenultimusnbsp;rolli queat.

C A-*


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iECLVAXlONVM. C A P V T XV.


I15


MetJjodus tranfmutandï zy^quationesCubicas comfojt-tas,in quibus fecundus terminus deefi,in eyËquatio-nes Cubic asfimplices, quando idfieripotefl.

^ Roponatur haec aequatio 3 mmx—00 o. Suppo-

........Vn-


namus*:ic,-—o,hoce{t,x


de, transformataxquatione, habebitur


z.


g. —3 nbsp;nbsp;nbsp;m^ZZ-

Z^


¦


3 mmzz—3 m*


¦»’ 000,


hoe eft, multipUcatis omnibus per z^, invenictur haec aequatio z^nbsp;nbsp;nbsp;nbsp;00 o j vela.® 00nbsp;nbsp;nbsp;nbsp;cujus radix eft

00 1»’ v nbsp;nbsp;nbsp;Qiije eft aequatio cubica fimplex.

Cognita autemejus radices., eritex fuprapofitis radix altera

X zo-^-. Quae femper eft poffibilis , cum z major fit

quamw.

Aliter. Supponatur zz z x mm OD oy critque


mm-


-zz


x'zo ——-“ • Vnde tcansformata aequatione habebimus

s.® -j, nbsp;nbsp;nbsp;—w®Xo, hoe eft, iie^OO — vgt;z^'J^m^ y cujus radix eft co i »^ V 4nbsp;nbsp;nbsp;nbsp;Qus rurlus aequatio eft

«übka fimplex. Cujus ope , cüm cognofcitur z , habebitur

m m 7^ ^ femper erit poffibilis.


* 00


Proponamr item haec aequatio nbsp;nbsp;nbsp;—mmx—»’ooo, fiip*

ponaturque zzzx-^mmOOOyhoc eft, x 30 —---V ndc

• nbsp;nbsp;nbsp;, ,nbsp;nbsp;nbsp;nbsp;z^ :immz* ^m*zz m^

S'tisiortmtcijBcjmtioiic xi^dcdiitwis

-i——w^OOo , hoeeft, s.®—»^z,^-f-Tw® 00 o.


^mmzz-


feu z^ 00 n^z^ — m^y cujus radix eft ü-’ X t»* P 1/ i»®— ‘^artlLnbsp;nbsp;nbsp;nbsp;Pnbsp;nbsp;nbsp;nbsp;Vnde


-ocr page 142-

114 nbsp;nbsp;nbsp;D E N A T V R A

Vnde patct, oporte«e rrfi non majus cfletjuam ^ n'y utasquatio haec CO iï.’ — locum obtineat. Nam fi majus fit, non pof-{êt propofita aequatio * — mmx—»’ CO o fic in fimpliceoinbsp;cubicam tranfmnaa^

C A P V T XVI.

Metbodus generalis, concernens ufitm fecmdarumradi-cunh ^2 toUendaJigna radicalia ex z^quatione propofita.

SI fiieriniduac squationes, inquibus eadcm litera reperitur, licet ipfas reducerecompasando cumduabus aliis, in quibusnbsp;h*c litera pauciores habet dimenfiones.

Exempli gratia, habeamus hafce duas aquationes x^-\-bxx •—acx — d^coo Sc x^Ixx-i-mmx — n^ZOo. Quibus tranf-pofilis,habebimus a:’ CO —i'xx ccx d^ öc x^ ZO lx x—nbsp;mmx-t-n^i ac per confequens./A-A; —mmx -f-»’ CO o, hoe

b -—cc —d^

mm x ccx d^ •

eft,afA:ao

l b

. in qua litera x pauciorum eft

dimenfionum. Atque uthabeatur adhuc alia, multiplicetur tan-

* nbsp;nbsp;nbsp;mmxx-^d^X

turn xquatio inventa per x, Sc invenietur CO

n\

l-^b

Qax comparata cum aliqua ex pracedentibus, verbi gratia, euffl fccttnda,exhibet fequentem aquationemnbsp;nbsp;nbsp;nbsp;—n^xIn^zoo»

• ee

—ll -^-bm'

—Ib

in qua litera x fimiliter duarum tantum eft dimenfionum. Sedli collata fuiffêt cum prima acquatione, inventafuifiet alia, ubi^nbsp;adhuc pauciores habu-ilamp;tdimenfionesgt;itauceligendafitad comquot;nbsp;parationem facillima. Atque fic continuando inveniri hic pol^nbsp;liint dus alis, ubi x eft unius dimenfionis , amp; tandem alia ublnbsp;prorfus deeft. Quod ipfum docet,dari tales zquationes,in quibusnbsp;litera, quaein utraque inveniri debet,, mutuailia comparatioucnbsp;plane aufertur. Vnde apparet, poflè quidem aliquando auferrsnbsp;hanc literam^quamvts non diminuaw nun^rus dimenfionum..

-ocr page 143-

jEq_vatioi»tm, ïiy

Exempli gratia, fi dentur hs sequationcs xigt;x-^c cODQ icxx—hx ddbbZOOt habebimusata:—hxZOCCt amp;nbsp;XXbxo^-^^bb—ddj ergotf 0C)bbdd.

Venio jam ad afymmetrias feu irrationales quantitates, pro quibus tollendis, oportet tantum fupponere litcras squalesfin-guiis terminis afymmetris sequationis propofitse. Qua quidem ra-tione non tantum obtinebimusjequationem propofitam, in quanbsp;omnes hae liters funt fubftituts; fed etiam tot alias, quot litersnbsp;ftterunt fuppofits. Vndecollatisordine omnibus hifcesquatio-Ribus, devenieturad squationem, ubi nullaliteraruminvenituf

per confequens nullum fignum radicale.

Exempli gratia,proponatur squatio c-^yc.bbxydx^o. Ad tollendas igitur ejusafymmetrias, ponamusi? co y C.bbx,nbsp;dx. Quibus in squatione propofita fubftitutis, habe-bimus c-\- R—2;, CO o; atqueex reliquis fuppofitionibus eritnbsp;bbx, 8CZ.Z.CO dx. Primo, ad tollendum R, habebimusnbsp;3^00 t.—c.ideoqueiJ’cOt.’—3 czz. ^ccz. — t». Atquieft

quoque bb x. Quare erit a,* — ^ czz. -t- ^ ccZ — t’_

i bx'JiOy amp; per confequens x.’co-h % t z. z.c ez.^ c^^bbx. Sed fi multiplicetur fuperius propofita squatio z.z.nbsp;CO .V pee habebitur etiam z.^ ZD d xz.. Ergo eritnbsp;^cz.z.— ^ccz. c^ CO o, amp;fubftituto^Arloco2i;t,, habebi-— dx •^bbx

taus'^ cdx— COo.hoceft, 3tc;t,C03 cdx-J^bbx»

— dx -^bbx nbsp;nbsp;nbsp;dx

K. ZO -—^-. Qus h multiplicetur per z., fiet

^ C C quot;i* d JC

3 cdxz bbxz. c^z.

czco

. Sed eft quoque zt CO AT. Igi-

^ C C 'T* d X

Habebimus 3 cdxz, •^-bbxz. t’zC0 ^cedx ~^ddxx,

boc cft, - j. ^ nbsp;nbsp;nbsp;3qnbsp;nbsp;nbsp;nbsp;Inventa autem eft

3 t lt;t X bbx-^c^

3 cdx'J^bbx’^c^ 3 cc dx

Quare habebimus tandem


-ocr page 144-

lï^ De NaTVRA iEQVATIONVM,

ccddxx-\-'^ c^dx — c^co o. In qua «quatione nul-— ebbed —ic^bb —. b‘^

lus terminus irrationalis reperitur. Quódfiautemalüadhucre-perirentur, oporteret tantum operando ut fupra auferre cjeteras literas, cseteris terminis irrationalibus aequales füppofitas. Quanbsp;quidem ratione omnes omnino termini 'irrationales tollentur,nbsp;calculus vero prolixior evadet.

Neceffitas hujusmethodi velhincpatet, quód, fifuerintplu-resquatuor terminis irrationalibus, fignaradicalia, per metho-dumaVietatraditam, Capite quinto deEmendationCi^Equatio-num 5 tolli non poffint.

FINIS,

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Ad Traöatum de Limitibus jïquationum .

EPISTOLA PR^LIMINARIS.

Clarijfmo Viro

FRANCISCOaSCHOOTEN,

Mathematum in Illuftri I^idenfi Academia Profefibri,

ERASMIVS BARTHOLINVS

S. P.

Ijl meminijfem, c^uanto majore animo honejiatis fruBus in confcientia^ qadmnbsp;in fama re-ponatur ; nequaquam op-portunum faijjet , in edendis hijcenbsp;opufculis udnalytiek conjllmm. erum cpatanbsp;'eommunihus magis commodis qudm pri'vatanbsp;'jaBanti^ judul, ei) animus mfus efi, delibe^nbsp;rato conjïlio obfequi. Cujusme^ confcientia in^nbsp;terpretem, non alium magis dejïdero, ójmm tè^nbsp;J^ir Clarijjme, quem utilitatibus aliorum yplmnbsp;qudm propria laudi,indies defer^vire^compertumnbsp;^nheo. V^enit in mentem jiudio/um illud otium^nbsp;^^od Leida mihi femper emolumento ^ utrifquenbsp;deinde folatio erat^ cujusque 'varietates ji oratio--rep eter e vellem, prout animo pier aque obuer-fnntur, non dubito quin exifïimationi hominumnbsp;diligentia ^ jides noflra, ^ inplerifque etiamnbsp;^ietas fubjiceretur. Etlicèt nefciam^ anullum

P 3 nbsp;nbsp;nbsp;tem^

-ocr page 146-

tem^m ]umndtus exegerim; tarnenedde caasd magnifacio, qmd amicki^ tua, afijue ad intunbsp;mamfamiliaritatem, capacem me redderet. Ne-que aliam inter^retationem hahuit, quod Leiddnbsp;aifcejptrus, Ifagogen Cartejimam tjfis excu-dendam concinnaveram, ut meam famam cumnbsp;tua extenderem. Qua de causd ^ cum non modonbsp;effenfas, 'verum etiam jïmultates 'varias fubie-vim j non ignoro, qu^ futura fit de htfee jamnbsp;edendisJèntentia. Ne duhites tarnen qsnn omnianbsp;aquo animo tolera'verim, -prajèrtim quiapetasnbsp;¦^'oifiequium caufamjunxère. Quemenimpa-terit, fatum Uteratorum? Adihicertè nonim^^nbsp;fro'vifa eft calumniandi'vanitas. Eftitanaturk compohatum^ut benefaBis major ex confeietunbsp;tia merceSf qudm in ore hominum refonatur:nbsp;nam fferiqm^ tantum fua: detraBum iri glorianbsp;exijiimant, quantum cefferit aliena: pjiremo,nbsp;ignaviffmm quijque aliorum fcrifta carperenbsp;non 'veretur. Sic contendere pro morihus tempo-rum eruditio efi. Quod recordantem, poflerita-tis magnamifiratio frbit. Quot enim pradaranbsp;ïn'venta putas ohfeurari, propter fcelus hoe ob-treBandi? Plerique fie intra perpetuum filen-tium tenere amant, potius qudm malignitati in-terpretantium exponi. Ita communem hum er-rorem, honum publicum magnk detrimentis ex-piahit. Ego aliorum exemplo quidem didici,

nul-

-ocr page 147-

nuUam ex mets tahorihus ^erare laudem y tanta tarnen mihifèmperfuit reverentiapoflerum , utnbsp;cenjuram erroris non tam reformfdem qudm in--humanitatis. Sedy ut depBoreniJt y^rtifexju^nbsp;dicare, ita niji Mathematum non fatispoteftnbsp;perjpicere Mathematica ; tu^ potijfimum fen-tentia h^ec exponuntur. Eximium hahent ufUmnbsp;ta quafequenti traBatu exponentur, ad nume-^ofam j^quationumvefolutionem y, ut reliquasnbsp;^tilitates pertranfeam , quia Eu eas ignorarenbsp;potes. G^uare LeBorés rogo , ut judkiisnbsp;'flt;trcanty donee penitus omnia injpexerint. Etnbsp;fi quifuerint qui hac recujd'verint, fciant fe neenbsp;in’venüs gratiam adimere, nee mihi laudü con^nbsp;feientiam. Ee ’vero, Vir Clarifjimey fi offen-derint , omnibus commendationihm defiitutanbsp;reputaho. Vak.

-ocr page 148-

P OSf ER /'O R r-RACTA TFS

DE

LI MITI BV S

Quo pafto ex forma iEquationum affèélarum definiri poffint limites, ititra quos radicesnbsp;ver» debentofïèndi.

DE

-ocr page 149-

Ill

D E

L I M I T I B V S

ACiVATIONVM.

G A P V T I.

'Tgt;e (i^quationum ^adratarimfiu duarum d'menjionum limitibus.

Trop. I. XV!Ix-^mm ao o.

Ertranfpofitionemerit mm ZD lxxx, 8c fiprima parsfaeriti-ealis, eritctiamaltera'nbsp;parsrealis, ideoque/xmajus quam x.v; amp;nbsp;divifoutroqueterminoper x, erit / majornbsp;quam x. Quin amp; per traiafpofitionempro-pofitte sequationis habebitur a:a*x/x—mm:nbsp;ideoque altera pars cftrealis, amp;/Amajusnbsp;quana mm. Vndedivifo utroquetermino

per /, erita; major quam nbsp;nbsp;nbsp;. Quare tequationis propofitse utra-

que radix AT major erit quam , fed minor quam/.

Trop.^. XXlxmmzDo,

Per tranfpofitionem habebimusArA CO /a: ideoque a a; ^ajus erit quamnbsp;nbsp;nbsp;nbsp;amp; x major quam/w, ac proin de»?xmajus

q^^am mm. Y nde x x minus erit quam /x m x, adeoque fi utra-pars dividatur per x, eritx minor quam l m. Rurfus, quo-niauiA xaequatur/x gt;»»?, eritxx majusquam/xj aeproinde * uterque terminus dividatur perx, erit x major quam /, amp;/xnbsp;**^^j^squam ll. Hinccumxxa:quetur lx -hmm, eritxxmajusnbsp;q^am//-}.nbsp;nbsp;nbsp;nbsp;hoc eft, x major quam y' ll fnmgt; Poftremo,

quandoquidem Xmajor eftquam»?, erit/xmajusquam/»?, amp; majus quam/»? 4-w?, hoc eft , x major quam Im-^mm.nbsp;ode radix tequationis propofitx erit major quam maxima ha-^omduarutny' llJ^mm8^'^nbsp;nbsp;nbsp;nbsp;fed minor quam/ ?».

//. nbsp;nbsp;nbsp;Qnbsp;nbsp;nbsp;nbsp;Prs-

-ocr page 150-

112}

De Limit! BV s

^ro^.l. Xx-\-lx — ;»waoo.

Per tranfpofitionem habebimus,v;f /;e 03w ȟ,8r per confc-quens^^ma;useritquara;v. Rurfusexiftente xx-\-lxZD

erit »*»* majus quam A;a:, amp; m major quam Ar,ac proinde w ar ma-jusquam XX. Acquihabemus xx-^ixzo mm. Eïgomx majus eritquamw#»?. Hinc divisautraque parte per »* /, fictat

major quam . Quare inventa eft at radix sequationis propo-fitSE major quam nbsp;nbsp;nbsp;at minor quam ~p oc m.

C A P V T II.

2)^ limit thus (•_/Equationum Cubic arum fiu triurn dimenJiQnum,fecundo termmo carentium.

Trop.ï. x'^*—mmx iigt; co o.

PErtraofpofmonetn habebimus x^zo-^mmxngt;y eritque

mmx majus quam Vnde divifo utroque termino per m

eritx major quam-^L . Deindeper tran^pofitionem erit«^«^a¦—

a•^CO»^, ac per confequens m m majus quam xx , 8c major quam ar. Quare inventa eftutraque radix araequationis propolita

major quam Sc minor quam m.

‘Prop.T,. x'^*mmx—zo o.

Per tranfpofitionem habebimus — mmx ZO n^ y eritquea?X majus quam »*gt;»,amp; x major quam wï.Erit quoque x^n^ZDmmXynbsp;ideoque at^ major quam»^, amp;a: major quam», ac proinde»» atnbsp;majus quam n^. Atqui per tranfpoiitionem propofitionis habe-masmmx n^ ZO at^ Quare«» 4-»» at majus erk quam a?’ gt;nbsp;amp; divisiutraque paree per at. erit?»»^4-«»majusqua.nA'at; ideo^nbsp;que X minor quam yquot; mm-{-nn. Inventa ergo eft x radix ;equa-tionis propofitïe major quam m Sc »,at minor quam y mm nn.nbsp;Atque liquet, ad evitandam extraftionem radicis cubicae ipfius»’»nbsp;quódloco «» in vinculo alTurai pollitquantitasaliqua,

-ocr page 151-

\^Q_VA TlONVM. nbsp;nbsp;nbsp;113

fit minor. Id quod nonerit diflScile, cognitis nempe tribus di-menlionibus iplius w^,fumendoque loco »» reólangulum fub dua-busquantitatibus; quarum akcrutra non fit ipsa «minor. Erit-que hoc ad fequentia notatu dignum.

3. nbsp;nbsp;nbsp;* mmx—30 o.

mm

Per tranfpofitionem Iiabebimus.v3 co — mmXy eritqiie

major quamar.Rurfus erit»»«?xCX)»^—confequenter major quam nbsp;nbsp;nbsp;major quam Ar,ac proinde nnx majus quam ar^Sed

per tranfpofitionem xquationis propofits eft quoqite x^-\-mmx:o «fErgo mmx-k-nnx majus erit quam »’,amp; divisa utraque parte per

erit a: major quam nbsp;nbsp;nbsp;Invcnta kaque eft radix aquot;

*quationis propofitae elfe major quam nbsp;nbsp;nbsp;gt; fed minor quam

~ 8c K. Poffumus etiam loco nn accipcrerecftangulumduarum

maximarum dimenfionum ipfius b^, utradicis cubicjeextradio evitetur.

Capvt III.

2)^ limitibus zyEquatiomm Cubicarum,pemltme termino cartntium.

Trof. I. — lxx*lt; 00 o.

Per tranfpofitionem erit a’ »’ 00 Ixxy ideoque x a majus quam j . Rurfuserit CO lxxx^, dc confequenter I majornbsp;Quslibet igitur radicum x^quationis propofitse majornbsp;^'^ftquam-j/^ , amp; minor quam 1.

Trof.TL. x^ nbsp;nbsp;nbsp;IXX*nbsp;nbsp;nbsp;nbsp;X o.

Per tranfpofitionem erit x^—lxxCDn\ ideoque a? major quam 1. Rurfus erit x^ODIxx, Sc confequenter x major quam », amp;nbsp;majus quam nn,Scnxx majus quam Atquihabemus quo-que per tranfpofitionem/ax b5 00 ark Quareerit Ixx nxx

ïnajus quam xk Dividatur utraque pars per xx, eritque/ »

Q, 2. nbsp;nbsp;nbsp;major


-ocr page 152-

1X4 De Limitibvs

major quam x. Inventa itaqueeft radix x sequationis propofitar major quam lamp;i n, fed minor quam / ». Manifeftum cft quo-que ad evitandam extraffionem radicis cubicae ex , quod loco »nbsp;lumi pofficminor triumdimenfionumipfius»^, quandomajornbsp;cftj amp; quando minor perhibetur quam/ «, quod tune loco»nbsp;maxima triumdimenfionumipfiusw^accipiqueat, amp;llcdereli-quis, quibus ob nimiam facilitatem non immoramur.

^rop.'^. x^-\rlxx*—go o.

Per tranfpofitionemeritCD»’ —•IxXyS.c per confequens ^

majus quamxx. Eft etiamIxxzon^ — x’, amp; confequenter«major quarax , amp; »A:armajus quam ar’. Sedhabetur arJ-p/arx X »’• Ergonxx lxxmajuseritquamhoe eft,divisautraque parte per n l, erit x x majus quamnbsp;nbsp;nbsp;nbsp;. Inventa eft itaque radix x

asquationispropofitx major quEti-j/ nbsp;nbsp;nbsp;, fed minor quam -j/^

amp; n. Demonftratur prxtcrea »».v4-/»a: majus eflequam»^, amp; /armajus quam»», amp; confequenter a: major quamnbsp;quandoquidem » major eft quam a;.

C A P V T IV.

‘De lt;i/Equatiomigt;us Cubkü, m quibus omnes termini extant.

‘Prop. I. a;’—Ixx mmx — xo.

jp Er tranfpofitionem habebimus ar’ — lx arx»’—m mar. Hinc

fi ar xquetur ipfi f, erit etiam ar ipfi nbsp;nbsp;nbsp;squalis. Ideoque, fi

viciflim/xqueturipfi hoe eft,/»? m X»’, eritfimilitcrar ra-*

dix xquationis propofitx xqualis ipfi nbsp;nbsp;nbsp;Prxterea firr’—Ixx

cft realis, hoe eft, ar major quam /, erit quoque »’ —mmx realis» amp; confequenter major quam ar. Quódfiautem eademquao^

titas ar’—Ixx nihilo minor fit, tranfponaturpropofita xquatio hac ratione / arar—ar^xw/war—-»’.Et quandoquidem fupponiquot;

-ocr page 153-

iE Q_ V A T I o N V M. nbsp;nbsp;nbsp;ïlf

tar Ixx — x^ elTe realis, hoe eft, / major quam a:, crit mmx

etiam realis, amp; confec^uenter major erit x quam nbsp;nbsp;nbsp;. Inventa eft

itaque radix xquationis propoGtai «qualis ipfi l amp; ipfi nbsp;nbsp;nbsp;, cum

duo hi termini jequantur. Et fi unam tantum habeat aut tres,qu5e-libet earum erit in tra hos limites, quando intequales funt j fi veró ïEquales, hoe eft, Immzo n'i fubftituto Imm loeo «’in aequatio-nepropofita, amp; dividendoper^—/, eognofcemus earn non habere aliam radieem in hoe eafu quam/.

Trop. %. x^ lxxmmxTi* co o.

Pertranfpofitionemhabebimusx^—mmXZD «^—Ixx, fi ergo X xamp;c mm funt tequalia, erit etiam x x ipfi — squale j amp; fi

warmajus eft quam?»?», erit quoque^ majusquamA-A:; Sefiar-v

minus eft quam m ?w, minus quoque erit ”-j quam x x. Inventi ita-

lt;}ue funt duo limites m 8cy ^ , quorum euilibet xquatur radix

squationis propofitar, fi fuerint sequales, hoe eft,fi /m m xqmnu ipli«’; aut necefl'ario inter duos erit,fi inaequales fuerint. Eadem

«ft ratio duoriim reliquorum limitum» amp;

Trojff. i- nbsp;nbsp;nbsp;— lx x—m m xzo o.

Per tranfpofitionemerit — IxxZD mmx n^, ideoqucA: ^^ajor quam/iRurfuseum per tranfpoft tionem fit x’’—mmx gonbsp;X q. «3^ erit X X majus quam mm,8ix major quam m,Sc mxxnbsp;quam mmx. Sedper tranfpofitionem eft quoque x’—«’00nbsp;X w* X, amp; per eonfequens x major quam » , amp; « x x majusnbsp;*iuam»’. Quinamp;per tranfpofitionem propofiixhabetur/xxq-^?«x q-»3 QQ x^, atque inventum eft ?» x x majus quam mmxyScnbsp;**xx majus quam ?z’. Ergoerit/xx'(*?»xx-}-«xx majus quamnbsp;Quocircafiutraque parsdividaturperxx,eritl m-^- « major quamx. Inventa eft itaqueradixxa’quaiionis propofuae ma-jpr quam /, ?«, amp; »,ledminor quam t-\-m-^n.

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126 nbsp;nbsp;nbsp;De Limitibvs

w1


PertranfpoGtionemerit x'^ mmxZDn^Ixx^ idcoque -j

majus quam x x. Sed eft quoque nbsp;nbsp;nbsp;CD —m m Ar,ideoque

major quamA;. At veröeft etiam/A;A;H-«1gt;wAr co —x^, amp; mm 1nbsp;nbsp;nbsp;nbsp;^

confeqnenter n major quamx; quare SiCnnx majus erit quamx^t amp; /»armajus quam Ixx. Atqui eftar^ lxx mmxODn^- Ergonbsp;nnx^-lnx mmx majus erit quam Sc x major quam

nn /”m ^' nbsp;nbsp;nbsp;inventa cft radix x asquationis propofitse

maiorquam -—7—;-, at minor quam 1/ ^ , — , amp;».

*Pro^. x'^lxx mmx n'1 od o.

Per tranfpofitionem eritmmx-^n^zolxx—x’, ideoque/major quam x. Rurfpserit x^ »’00/xx'—?wwx, amp;per confe-

quens X major quam Invenimus ergo,quamlibec duarum ra-

dicum jequationis propofits necefl'arió majorem efle quam amp; minorem quam/. Sed per tranfpofitionem eft quoquex^ »z?»xnbsp;Cd/xx —nbsp;nbsp;nbsp;nbsp;confequenter XX majus quam ^. Qiiareamp;xma-

jor erit quam-j/^ .

7rop.6. x'^-\-lxxramx^fi^ co o.

Per tranfpofitionem eritx^ Zxxoo mmx—ideoquex major quam ~ , Similiter eritx^ «^ qqnbsp;nbsp;nbsp;nbsp;—^/xx,amp;per

confequens” majorquamx.Rurfuserit/xx B^cow^wx—-v’»

amp; confequenter m major quamx. Invenimusergo, quamlibct duarum rad'cum aequationis propofits neceffario majorem eflê

^uam ^ , fed minorem quam ^ amp; m.


1

Pr0‘

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^q_vationvm. nbsp;nbsp;nbsp;1x7

7rop. 7. nbsp;nbsp;nbsp;— lxXmmx n^ ZDO.

Per tranfpofitionem eritx’ — lxx'j:gt;mmx — nbsp;nbsp;nbsp;Vnde pater,

fi a: sequalis eft ipfi /, quódtunc quoque a: ipfi — eft asqualis.

Ideoque fi/sequaturipfi^-^, hoe eft,/?»*wCO »’,una radicum x-

q^ationis propofitte squabitur fingulis terminorum /amp; nbsp;nbsp;nbsp;; amp; ft

•n^qualesfuerintj neutra ex duabus radicibus squationis propo-fitï poterit efle inter hos terminos. Qpia videmus, cum x major

eft quam /, mm quoque x majorem clïe quam nbsp;nbsp;nbsp;•, amp; ft minor eft

quam /, tum fimiliterx minorem efle quam nbsp;nbsp;nbsp;Sed per tranfpo

fitionem eft etiam —mmx^ lxX—Hincfi xx sequetur ipfi ww, erit quoque XX GO ^ . Ideoquefifucrint hi termini

amp; ^ xqualesj hoe eft,/»«m GO una radieum sqtiationis pro-

pofits major erit unoquoque terminorum tequalium m amp; nbsp;nbsp;nbsp;^ ,•amp;

fi inaequales fuerint, neutra duarum radieum sequationis propofi-tje erit inter duos ex his terminis. Pr^terea per traufpofitionem eft quoque x’ »’G0/xx-4-»?»?x, ideoque lx x-^-mm x majus^nbsp;quam x3,amp; lx-\-mm majus quam .vx.Atx erit realis, amp; vel xqua-fis, vel major, vel minor quam m, fi arquatio propofita fuerit rea-fis. Et fi jequalis fuerit vel major quam w, erit amp; lx w x majusnbsp;S'-'^m X X, ac per confequens l-\-m major quam x. Quód fi au-ïem minor fuerit quam w, multomagis/-|- /w major erit quam x.nbsp;^orrb ex hac eadem squatione eonftat, quod/x x-H w* w? xetiarn;'

eft quam n^. Hinccum l-\~m major fit quam x , ideoque IIXnbsp;nbsp;nbsp;nbsp;majus quam /x.v; erit quoque //x /x-^-mmx ma-

quam «5, amp; xmajor quam nbsp;nbsp;nbsp;• Invenimus igitur,.

H^od quslibet radieum aequationis propofitx major eft quam

, amp; multo major quam

at minor

--------- lt zlm mm ^

Suam l m. Denique.quoniam /-lt;-»? major eft quam x, fi major ftierit Xquam m, erit inter hofce terminos 1 n: amp; m. Quod ftnbsp;''^®ró m major eft quam x, invenimus, quod Ixx-i^mmxdï ma-

jus,

-ocr page 156-

ii8 nbsp;nbsp;nbsp;DeLimitibvs

jus quam«’, \\\x\Q,lmx nbsp;nbsp;nbsp;multo magiseritmajus quam»^;

adcoque a;major quam Ymquot;^mm* ^ coi^^^quenter ar major quam

ni


minor horum duorum terminorum m 8c


/m mm'


C A P V T V.

*De (:_/Ëqiiationibus qiiatuor dimenfionum ,fecmdo amp; tertio terminocarentibus.

Trop. 1. x‘^ * *x ZD o. jp Er tranfpofitionem eft ar'* CD x—p'*, ideoque ar major quatn

^ . Sed per tranfpofitionem eft quoquep OQ«’ar—x\ amp; coa-fequenter major quam ar^, ac » major quam ar. Ergo utra-que radix ar aequationis propouts major ent quam ^ , at minor quam n.

Tro^. 1. x‘^**X—CD o.

Per tranfpofitionem eft a:'* — n^xzop'^, ideoque ar^ major quam n^,8c X major quam k, 8cnnx x majus quam ngt; x. Sed eft quoquenbsp;arquot;* —pquot;* GO ar, ideoque ar'* majus quam p'*, amp; ar major quamp, amp;nbsp;pp XX majus quam pi At per tranfpofitionem eft etiam»*ar nbsp;p‘‘CDarl ^xgonnxx ppxx majus erit quam ar'*. Hinc divisanbsp;utraque parte per ar x , erit ar ar minus quam nn-^pp, 8c x minornbsp;quam-y/ nn-\-pp. Invenimusigitur,quod radix aequationis pro-potu£E eft major quam « amp;p,fed minor quam yn n pp, ac proija'nbsp;de multo minor quam » p.

Trop.^. X* * * -f-fpAC—CD O.

Per tranfpofitionem erit ar‘*CDpquot;*'—ar, ac per confequcns^

majorquamar. Similiter erit ar cx) p‘*—ar'*, amp; confequenterp^ majus quam arquot;*, amp;p majorquamar, Stp^a* majus quam a.quot;*. Sednbsp;eft prsterea ar'* »’ ar CDp^ ideoquep^x n^ x majus quamp^S^

ar major quam nbsp;nbsp;nbsp;• Invenimus itaque, quod radix rrquationis

• nbsp;nbsp;nbsp;'nbsp;nbsp;nbsp;nbsp;P'* o

, at minor quam^ ocp.

propofits eft major quam

Ca-

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jEQ_VATlONVM.


119


Cap


VI.


(^^/Ëquationibus quatuor dimenfiomm, in quibiis ter this amp; quartus terminus deficiunt.

Tro^.ï. x‘^ — /a;3 * *XI o. jpEr tranfpofitionem eft a:‘*x /ar’—ideoquear’majornbsp;quam^ . At verö eft etiamp'^ZDlx^—¦aquot;’, amp; confeq—


iien-


ter/ major quama'. Invenimusigitur, quódunaqujequeduarum

radicum squationis propofitse eft major quam ^ , at minor

quam/. Hincquoniam/major eft quam a, amp;/a’majusquamp'', habebiturllxx majus quamamp; conftquenter xx majus quam


PP


jj , amp; a major quam Y

’Prop. z. X*Ix^ * * —X o.

Per tranfpofitionem efta** — /a’x/’Sidcoque x major quam /. Similiter eft a'*—p'* X /a’, amp; confequentera'* majus quamp^,amp;nbsp;a major quamp, acproindepa’ majus quamp'*. Sedeft etiamnbsp;/a’ p'^'X x‘^. Ergo/a’-Hpa’majus erit quam a^,amp;/ p majornbsp;quam X. Invenimus igitur, quód radix a squationis propofit*nbsp;tnajor eft quam I8cp,a.t minor quam l p.

Prop-i- x‘^’^lx^**—p‘' X o.

Per tranfpofitionem eft a'* xp'*—/a’ideoque^ majus quam

Similiter eft/a’ X p*x\ ac per confeqüens p major quam a, ^ p a’majus quam •v'*. Atqui eft etiam a'^ Zar’Xpquot;*. Ergo /a’

p a’ majus erit quamp^, amp; a’ major quam nbsp;nbsp;nbsp;. Quare inve-

iiimus , quód radix a aequationis propofits major eft quam V C. j fed minor quamp ScyC-y . Facillimè veró evitan-

tur extradiones radicum cubicarum , fumendo terminos pauló ’’’ajores aut minores, prout neceffitas requirit. Atque in hoe ca-II.nbsp;nbsp;nbsp;nbsp;Rnbsp;nbsp;nbsp;nbsp;fu,



-ocr page 158-

130 nbsp;nbsp;nbsp;DeLimitibvs

fu, quoniamx'^ major eftquam nbsp;nbsp;nbsp;, amp;p major quamA;,eritpxx

majus quam^-^^, amp; jfArmajusguam nbsp;nbsp;nbsp;amp; a* major quam

y nbsp;nbsp;nbsp;. Praterea,quandoquidem^ majus eft quam erit

-majus quam , amp; Ippx majus quam Ix^, quia^ major eft

quamX Atquieft a‘* /x5 00/gt;“*• Ergo^ lp px majus erit quamy. Hinc, multiplicatautraque parte per/, amp; divisaperpjo,nbsp;habebiturppx //Amajusquam//gt;p,amp;A'major quam

De xquationibus quatuor dimenfionum, inquibusfecundus amp; quartus terminus deficiunt, nihil addimus: (iquidcm iliaeadnbsp;quadratas referuntur, itaut ipfarum limites eodem modo quonbsp;quadratarum inveniri poffint.

C A P V T VIL

De cyS^uatiomhus quatmr dimenfionum, fecundo termtno carentibus.

Drop. I. nbsp;nbsp;nbsp;—mmxx n^X—co o.

PEr tranfpofitionemeritx^mmxxZDp* —Vndeappa-ret, quód, 11 fueritxxaequale ipli mm, hoe eft, xCO m, etiam

X nbsp;nbsp;nbsp;fit aequalisfutura.Ideoque 11 fuerit «ixqualisipfi^, hoe

eft, «*»’C0p‘', radixaraequationis propofitasaïquabitur fingulis é terminorqpi mamp;^ ; 8c fiinsqualesfuerint,unaquaeque radicum

ajquationis propofitje, fiveunam live tres habuerit, fempererit inter duos hofceterminos. Prastereacognofcitur, fi duo hi termini fuerint aequales, hoe eft, mn^ZDp^lubftituto m locop* innbsp;xquatione propofita, eaque divisa per jf —m, fore, ut non poflitnbsp;habere aliam radicem realem praeter m.

DroP’

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iEQ_VATIONVM.

Trop. z. x** mmxX — n?X—^^cx) o.

Pertranfpofitionemhabebimusx‘*xZDp^mmxx.Ya-deconftat, fiArajqualis fueritipfi «, foreetiam xxZD boc

eft, X GO V-^ nbsp;nbsp;nbsp;^amp; fi fuerit n oo-t/JL aut ^,tunc radicem

«equationis fore aequalem cuilibet borum terminorum; amp; fi in-«quales fiierint, tunc earn necefl'ario futuram inter bofceduos.

Idem demonftrabitur de duobus reliquisjt» amp; nbsp;nbsp;nbsp;; ncmpe fi fiie

rint a:quales, radix xquationis propofitse arquabitur unicuique il-lorum duorura; fin inxquales, necefl'ario conftituetur inter duos, tranfpofita fcilicet sequatione in hunc modum a‘‘—p‘^ oo «^v—gt;nbsp;*»wxx.

Trop. 3. A?**—mmxxti^xp^ go o.

Per tranfpofitionem erit;e‘‘ — mmxx GO x f*, ideoquex at majus quam mm,amp;c x major quam w,amp; m x^ majus quam m m xx.nbsp;Sedeft e.tiam x^n^xODmmxx-i-p'^t ideoqucA^^major quamnbsp;n\8cx major quam «, amp; » a;gt; majus quam at. Eodem modo eftnbsp;—p* j:) mmxx n^ x,Sc confequenter Ar'^majus quamp'', amp; xnbsp;niajor quamp, Sip x^ majus quamp'*. Atqui per tranfpofitionemnbsp;^ftquoque mmxx n^ x-f-p‘*OD x*. Quare mx^ nx^ px^nbsp;®ajus erit quamA:^, amp; m-\-n p major quam a;. Confimilira-rione demonftrabitur,quod w« mxx-\~nnxx-\-ppxx majus eritnbsp;‘I'lamAr'', amp; confequenter mm nn-{-pp majus quam x at. In-^enimus ergo , quod radix x propofita: aequationis- major efl:nbsp;^Uam m, n,Sip,zt minor quam m-\rn p, Scy^m m n n p p.

7rop.^. x^*-\-mtnxx-\-n^Xp*ZDO.

Per tranfpofitionem eft xquot; -E nbsp;nbsp;nbsp;x x GO p'* —n^Xy ideoque ^

^^ajus quam X. Similiter eft x** »’ x GO p”*—m w? x x, ac per con-

R a nbsp;nbsp;nbsp;fequens


-ocr page 160-

131 nbsp;nbsp;nbsp;De Limitibvs

fequens majusquam xx, hoceft,^ majus quam x, Atqui

eft qiioque mmxx n^xZDp*x‘^, amp;confequenter/) majus quam x'*, ac/gt; major quam x, amp; /^^^-majus quama;”*, nee nonnbsp;mmp Xmajus qaïmmmxx. Sedeltetiamx'* mmxx n^xZOpquot;^-Qiiarep^x mmpx n^x majus eft quam /gt;“*, aeper confe-quens, divisautraque parte per «?»?/) »’, erit radix x pro-

pofita: üiquationis major quam nbsp;nbsp;nbsp;; at minor quam

e,ü-,amp;p.

«3 W ’ nbsp;nbsp;nbsp;'

Trop. 5'. nbsp;nbsp;nbsp;—mmxx n^ Xnbsp;nbsp;nbsp;nbsp;zo o.

PertranfpoGtionemeft«’xH-p'‘ zommxx—x^, ideoquew»* majus quam XX, amp;«? major quam x. Similiter eft x^ pquot;* co

mm XX — X, amp; cbnfequenter x major quam —-. PrEEterea eft

x‘^^n^xzDni7nxx—pquot;*, aeper confequens xx majus quam

— , hoe eft, xmajor quam Invenimusergoquamlibet ra-

dicum xquationis propofitte majorem efte quam ^ Se ^ gt; at mi-norem quam m.

‘Pro^.6, x‘^*-\-mmx X— n^ x-^p^zD O.

Per tranfpofitionemeft x'^ ^^xx GO n^x—p‘*,ideoquex major quam ^ . Sedeftetiam x'^ p^Qo »’x—mmxx^ aeper

confequens majus quam x. Similiter eft xquot;* w»2xx p^

ZOn^ X, ideoque major quam x'^, 8c n major quam x. Inveni-musergo quamlibet duarum radicum tequationispropofitae majorem efl'e quam ^ gt; at minorem quam amp; ».

Trop. 7- x‘^*mmxxn^x p'^ zo o.

Per tranfpofitioncm eft x^'-—mmxxZOn^x—^p'*. Vndepa*

tet,

-ocr page 161-

iECLVATIONVM. nbsp;nbsp;nbsp;133

tet, fi ar aequatur ipfi w »?, hoe eft, x CO «/, eandem x fore ïqua-lem ipfi^ ; ac per confequens, fifuerint termini hi ~ xqua-

les, eritunaradicumsquaponispropofitïEa’qualis fingulis ipfo-rumj amp; fi insequales fuerint; neutra duarum radicumsquatio-

nispropofitse poteritefle inter illos duos. Eodemmodo

pertranfpofitionemeftxquot;* — n^xco rnmxx—pi Vndehmiliter difcimus, fi x’ arquatur ipfi ngt; , hoe eft , x 00 «, fore etiam

XX CD hoeeftjXGO^. Ideoque fi hi termini» amp;^fueiint

®quales, unaex radieibus sequationis propofits tequabitur fingulis eorundem terminorumj fin veró inxqualcs fuerint, nulla radieum xquationis propofitx inter illos duos conftitutaerit. Erxcerea per tranfpofitionem eft xquot;*nbsp;nbsp;nbsp;nbsp;CD «i» x x x, idco-

«^ue^^w^xx w^xmajus quai-nxquot;*, Sc mmx n^ majusquamxl Porro, fi propofita atquatio eftrealis, eritxrealis, amp;2qualis,nbsp;vel major, vel minor quam n. Si fuerit xqualis vel major, eritnbsp;mmx nnx majus quam x’, 8c mm nn majus quam x x, hoenbsp;eft, X minor erit quam 3/ mm-^nn. Si fuerit x minor quam »,nbsp;minor etiam erit quam 3/mm-\-nn- Qiiarc patet, quamlibetnbsp;radieum aequationis propofitae neeeflariö minorem efl'c quamnbsp;mm •\-nn. Deniqueexiftentex'* pquot;* CDnbsp;nbsp;nbsp;nbsp;xx x, erit

fimiliter mm xx x majus quam pl Etquia inventa eft •y mm nn major quam x,erit confequenter mmxy mm nnnbsp;naajusquamzwiwxx, ideoquewx3/»?»« »«, «^xmajus

quamp'^jamp;r x major quam-


Quare inventus

mm y mm nn, m3

eft terminus unus major amp; alter minor quam quselibet dua-J^utn radieum Eequationis propofitae. Atque ita modo fequenti capiteobfervatopropofitione feptima demonftrari poteft, quod

* major eft quam minor horum terminorum n amp; nbsp;nbsp;nbsp;•

Ca-

R3

-ocr page 162-

Ï34

De Limitibvs

Ca PVT VlII.

lt;iyEquatiombus quatuor dimenjionum, petmUimo termino carentibus.

TroJ^.i.Ix^ mmx¦:d o.

jpEr tranfpofitionem eft nbsp;nbsp;nbsp;— mmxx. Vndecon-

ftat, fi X eft ^qualis ipft /, etiam x x sequari , hoe eft.

fP

X 00^ ideoquefi/£EqaaIiseftipfi^*’,hoc eft,/zwGOpp ,eritra-«

dix jequationis propofit* jequalis fingulis terminorum/8i^ ; 8c

fifuerintinaequales, unaquxqiie radicum a’quationis propofit£e, five unam, five tres habuerit, lemper erit inter hos tertninos; fednbsp;fi fuerint aequales, hoc eft, / w CO pp, Scllmm3Dp*y fubftitutonbsp;llm m loco pquot;* in xquationc propolita, caque divisa per x—/, C0“nbsp;gnofcemus in hoe cafu non haberi aliam radicem veram prse-ter l.

Trop. z. x^¦\-lx^ — mmxx*

Per tranfpofitionem eft x*mmxxZDp*Ix^. Vndecon-ftat, fifueritx 00 w, etiam y C.y aequari ipfi x-, ideoque fi duo

termini »«amp;-y/ C.^ fint sequales, etit radix a:quationis iqualis

fingulishorumterminorum; finveróinsequalês fuerint, eritilla neceffarió inter duos. Similiter per tranfpofitionem eft .v*—p'*0Onbsp;mmxxIx^. Vndedifeimus, quod fixxqualis eft ipfip, fore

quoque earn squalem ipfi^^; ideoque fi terminip amp; nbsp;nbsp;nbsp;squan-

tiir, eritr;idix asquationis squalis unicuique illorum; fedfiin-asquales fuerint, erit ilia neceflario inter utrofque conftituta.

^rop.i.xquot;'Ix'^mmxx*—p‘^ ^ o.

Per tranfpofitionenleft /x’ co mmxx p* t ideoquex

major

-ocr page 163-

^q_vationvm. 135-

major^uam/. Sed amp; pertranfpofitionemefta:''^—mmxxZDlx^ 4-pquot;-, ideoquexmajor cjuam w, amp; mmajus quam mmxx. Similiter per tranfpofuionem eft —p^ZOlx^ ”fmx A'jideoquenbsp;* major quamp, 8c px^ majus quampi PriEtereaper tranfpoli-tionem propolitioniseiilx^ mmxx p‘^OD x^j ideoqueix^ nbsp;^x^ p x^ y majus quamAf^, amp; / »* p majus quamx. Qiiare

nimxxy8Lxx majus quam lx-\-inm. Atqui demonj^ratum eft fu-perius at majorem effe quam /, ac proinde//minus quam /at. Mul-toigitur magis atat majuseritquam//-f- «?/w, amp; a:major quam ^nbsp;nbsp;nbsp;nbsp;Non diffimili ratione demonftrabitur, quód at ma

jor eHquamy y/‘’ p‘^gt; Vy »si‘*-4-p‘', amp; y ymmpp p*.

Trop. 4. -\~lx^ mmxx * oo o.

Per tranfpofitionem eftA-‘* /a:’ gop** —mmxx,ïdcoq\ie

majus quamATA:, amp; ^ majus quam Ar.Similiter eft a;‘* ;w/» at a'GO

p*/x^, ac per confequens p major quama;, amp; ppxx majus quamar^ , amp; Upp majus quam/at’. Sed per traofpolitionem propolitionis eft cinmx^^ Ix^ mmXxZDp'^. dnzKppxx lp x a:nbsp;quot;^mmxxmaju%eritquamp^^, 8cxxmajusquam^-^^^^-|-— ^amp;

* major quam nbsp;nbsp;nbsp;exiftcnte x^ lx^

Ar a: GO p'*, erit quoquep't majus quam/at^, ideoque^ majus ^OaniAr^, 8cy C.^-p majus quam at. Inventa igitur eft radixATS-^uationis propofitJE major quamnbsp;nbsp;nbsp;nbsp;; at minor quam

^^yc. t,amp;p.

Trop. 5’. x^-‘lxfl-^mmxx* p‘^zD O.

Per tranfpofitionem tiimmxx p*0:)lx^— .v**, ideoque /major



-ocr page 164-

136 nbsp;nbsp;nbsp;De Limitibvs

11:

jorquam.v. Deindeefl: x‘* p'^2Dlx^mmxx, acpePconfc-quensxmajorqiiam. Prseterea t^x^ -^mmxx ZD bx^ —pquot;*,

acproinde x^ major quam^ ,amp;ar major quamyc. ^. Inveni-mus igitur, unamquamque duarum radicum sequationis propofi-tEEmajorem eüequam -j- amp; y C.j , at mmorem quam/.

^ró^.6. x^ lx^mmx

Pertranfpofuionemeft;e‘'^ pquot;^30?w?»A:ar—ideoque ^

majus quam ar. Deinde eft/a;^ -j-p'* GO mmxx—at^^ ac proinde aw major quam ar. PrEEtereaeftar'^ Zar^co «^J^ara*—pquot;*, amp;con-

fequentcr ar ar majus quam hoe eft, ar major quam^ . Inve-

nimus ergo, unamquamque duarum radicum EEquationis propo-

fitEE majorem efle quam ^ , at minorem quam amp; m.

^ro^. 7. nbsp;nbsp;nbsp;— Ix^mmxx* p^ go o,

Pertranfpofitionemhabebimusarquot;*—/ar^GO mmxx—p^ Vn'* depatet, fiarsequaliseftipfi/, ipfam ar quoque foresqdalem ipft

^ ; amp; per confequensjiifuerint termini/amp; ^sequales, erituna

radicum EEquationis propoiïtEE sequalis fingulis illorum; amp; fi fue-rint inaequales , neutra duarum radicum aequationis propolitEE poterit effe inter illos duos conftituta. Eodem modo periranf-pofitionemeftar'*—mmxxCO Ix^—Vndefimiliter conftat,

iifueritarEEqualis ipfi m, fore quoque araequalem'iph Y C.^ i

ideoque fi EEquales fuerint mScY^'Y ’ radicum asquationis

propofitEEsequaliseritcuilibethorum terminorumxqualium; amp; fi fuerint inaequales, nulla radicum aequationis propolitEE erit inter illos duos conftituta. Porró per tranlpofitioncmeft quoquenbsp;xquot;* p‘^ZOlx'^-\-mmx. ar,unde Ix^ -{¦mmx x majus erit quam ar'*»nbsp;amp;/ar-p rw?» majus quam ara'. lamfifuerit Ecquatio propolita rea-

lis,

-ocr page 165-

(i. V A T 1 o N V M. nbsp;nbsp;nbsp;157

^is, crit ^evel squalis, vel major, vel minor qiiam m, amp; I m major quam x. Quód ft fuerit x minor quam m, tnuko magisnbsp;ipfa minor erit quam / m.

Deinde ex eadem sqnatione x*-^p^ZD Ix^ mm xx etiain conftat, quod/x’4-«» gt;wa:Ar majuseit quam p‘'. Atquiinventanbsp;eft / ?» major quam x. Ergo//xx q-Zwxxmajiis crit quamnbsp;amp; llxx -^Imxx mmxx majus quamp*, idcoque xx

«Bajusquam --Hinccum//xx 2 /«vxx ^ mxx

mulcó majus{itquamp'*, eritquoque perconfequens/ar ?»x majus quam p p y Sc x major quam . Quare invenimusnbsp;quamlibet duarum radicum squationis propofitje majorem eflenbsp;quami/ -n—r^-- atminorcraquam/ »».

^ nbsp;nbsp;nbsp;' ll-\-lm-^rnm l mnbsp;nbsp;nbsp;nbsp;a

Caeterüm quoniam invenimus, quod x neceflario eft minor quamZ w; patet, fixTupponitur major quam»?, earn fore inter hos terminos / »?amp;»?. Quodh m fuerit gqualis aut major quamxj quoniam Ix^ mmxx majus eö: quamp'*, eritamp;

/»?xx »?wxx majus quamp%amp; XX majus quam nbsp;nbsp;nbsp;, amp;

a: major quam Y nbsp;nbsp;nbsp;• Quare unaquxque duarum radicum

«quationis propofit* major erit quam minor duorura termino-—-—-j at minor quam/-Hw.

’ Im mm' nbsp;nbsp;nbsp;^

C A P Y T IX.

2)^ limitibus i^^/^quationum quatmr dimenfiomm tertio terminocarenüum.

5Pr^. I, nbsp;nbsp;nbsp;—/AT*nbsp;nbsp;nbsp;nbsp;4 33

p Er tranfpofitioriem eft x^ — Ix^ ZDp* — tt^ x. Vndc patet^ quód ft X squalis eftipfi/, fore quoque x squaieraipfi C .

idcoque ft fueritZaequalis ipü ^ gt; hoe eft yln^ZOp^t tadix atqua-11. nbsp;nbsp;nbsp;Snbsp;nbsp;nbsp;nbsp;tionis

-ocr page 166-

138 nbsp;nbsp;nbsp;De Limitibvs

tionis propofitx sc^ualis eritfingulis ccrminorum / amp; ^ nbsp;nbsp;nbsp;amp; fi

fuerint in£EquaIes, unaquseque radicum aequationis propofits, five uiiam, five tres habuerit, fcmper eric inter hos terminos. Prte-terea cognofcimus, quód, li fuerint hi ultitni termini tequalesj^ hoceft, 30/’“r fubftitiitoin aequationepropofita /«Mocop'*,.nbsp;amp; divisa xquatione per x—/, ipfa nonpollic aliam habere ve-rain radicem quam l.

7rop. t. x‘^ 1AT —00 o.

Per tranfpofitionem eft x*n^xZDp'^Ix^. Vndeconftat^ fi X sequalis eft ipfi », fore quoque x^ 30 j ,ho,c eft, x ZO Y C. :

amp; fi fuerit«aequalis ipfi Y C.y, radix ^quationis aequabitur fin-

gulis horum terminorum; amp; fi fuerint intequalcs, erit neceflario inter duos. Deinde per tranfpofitionem eft a;'*—p'* 30 xIx^.

Vndepatet, fi fuerit arsqualisipfip, fore quoque ar at 30 y jhoc

eft, ar co y ^ J ideoque fi fueritp atqualis ipCiYy gt; radix aequa-

tionis propofitjE sequabitur fingulis horum. terminorum,amp; fi fuerint inaequales, erit neceflario inter utrofquc.

^rop. 3. AT'* — Ix^ * —ff X'—zo o.

Per tranfpofitionem eft xquot;*—/x’30»^x p'*, ideoquexma-jor quam/. Eodemmodoeft xquot;^ — x30/x^ p‘', acproinde X major quam », amp; » x^ majus quam x. Similiter eft x*—ptnbsp;00/x’ »’x, ideoque X major quam p, 8c p x^ majus quamp'**nbsp;Sed per tranfpofitionem eft quoque /x’ «^x p4 30 x'*. Qua-re /x^ x^ px^ majus erit quam x\8c 1 n p major quam x-Ergo invenimus radicem x aequationis propofits majorem eflenbsp;quam/,w, amp;p, at minorem quam l n p. Porró ex hac s-quatione/x^ x p‘*30 x'^etiamconftatjquod/x^ B^xeftnbsp;minus quam x^ : amp; quandoquidem invenimus / minorem eflenbsp;quam x, erit /* x minus quamlx^deoque f x-\-ngt; x multo min'i®^nbsp;quam x\ amp; x^ major quam /gt; -f- »h Non diflimili ratiqncdemon-

ftrabitur,quQdx major eft quam YY i‘^ p‘^^Y Y

^ro-

-ocr page 167-

^Q_VATIONVM.

Pro/.4. x^ lx^ nbsp;nbsp;nbsp;CO o.

Pcrtranfpofitionemcft at^ Zat’C0/)‘' — «^a:-, ideoque^^^ ma-jusquamAT. Eodemmodoeft x'^ n^xCO ƒgt;¦* — ac proinde ~ majusquaniA;^ Similiter eft/a;’ »’a; CO— Ar'*,amp; pcrcon-

fequens p majorqiiam at, amp; p* Armajusquam a:quot;*, ac/ppArmajus quam / x’. Scd per tranrpoiitionem propofitionis clt quoquenbsp; nbsp;nbsp;nbsp;nbsp; «^x oop'*. Quarep^x /ppx «’xmajuserit quam

pS amp;x major quam

pJ lpp ngt;

quationis propofitse major quam ~—

S .yc.^^,amp;p.

Etfic inventa eft radix xae-

^rop. 5'. nbsp;nbsp;nbsp;* ^3nbsp;nbsp;nbsp;nbsp;qq q.

Per tranfpofitionem eft x q-p4 co /x* — x*, idcoquc /major quam X. Deinde eft x^ p'* cD/x’ — x, quareeritxxmajusnbsp;quam-p j hoe eft, x major quam quot;j/ ~j . Sed eft quoque x‘' »3_j-

00 /x^ —pS ideoque x’ majus quam ^ ,amp; x major quam |/C.^ . Quare invenimus, quod quïlibet duarum radicum sequationisnbsp;propofita: neceflarió major eft quam y ^ amp; -j/C.‘^ , at minornbsp;«luam /.

Trop. 6. nbsp;nbsp;nbsp;00 o.

Per tratirpofitioncm eft x^ p‘* 00 «3 at—/x’, ideoque ^ ma-jws quam x x, hoe eft, x minor quam ^ • Deinde eft x^ /x*

X»3_^—p4,ideoquexmajorquam^ . Praeterea eft/x^ p^co

a; —. nbsp;nbsp;nbsp;amp; idcirco «3 major quam x^, hoe eft, x minor quam n.

Ergo invenimus, unamquamque duarum radieumxsequationis

propofttse majorem efle quam ^ , at minorem quam ^

S z nbsp;nbsp;nbsp;Prö-

-ocr page 168-

140

De Limitibys

Trop. 7. x‘*Ix^ *x-i-p* co o.

Per tranfpofitionem habebimus nbsp;nbsp;nbsp;—Ix^COn^xp*. Vr?*

dc patet, fi x sequalis eft ipfl / fore quoque x xqualem ipfi

^ j amp; per confequens, {ifuerinthitermini/amp;^ sequalesjhoc

eft,/»’ CDp^ , unacxradicibusa:quationts propoftt*ajqualiserit

fingulis horum terminorumjequalium/amp; fiinsEqualesfue-

rint» neutra duarutn radicutn aquationis propofits poteritefle inter jpfos. Deinde per tranfpofitionem eft x'*—n^xCD Ix^f*.nbsp;Vndelimili modopatet, fix^equatur ipfi», ipfamxquoquese-

quari ipfi y C. ^ , ideoque fi termini hi» amp; C. ^ jequales fue-

rint, unaradicumaequationis propofitae sequabitur fingulis horum terminorum aeqtialium; amp;fifuerint inaquales, nulla radi-cum aequationis propofits erit inter utroftque. Porró per tranfpofitionem eft quoque xquot;* GO /x’ »’ x,, ideoque /x’ »’ x majus-quamx'’, amp;/xx4-»’ majus quam x’. lam fi fueritpro-pofita squatio realis, eritxrealis, amp; vel aequalis, vclnaajorvelnbsp;minor quam m. Quód fi fuerit aqualis vel major,erit Ixx nxXnbsp;majus quam x’. Sinvero minor fit, erit x multó minor quan»nbsp;Quareutraque duarumradicum propofitxxquationisne-celTario minor erit quam / ». Quin amp; exiftentex‘‘-|-p^ GO /x’nbsp; »’x, eritquoque /x^ «’xmajusquamp^. Atquiinvenimusnbsp;l n majorem efl'e quam x, ac proinde ll nn z In majusnbsp;quamxx,nbsp;nbsp;nbsp;nbsp;z lln majusquam/xx, necnon/’x-f*

/»»x 2 //«X majus quam/x’. Ergo/’ X- -/» »x 2 llnx-iquot;

»’x majus erit quam amp; x major quam ^3

Et quandoquidem cubus ex / » major eft quam 1^ Inn-ir 2 //» -J-»’, multö magis erit x major quam p* divifum per cubumnbsp;ex / ». Invenimus itaque quód quxlibet duarum radicum *quot;nbsp;quationis propofitx major eft quam p* divifum per cubum ex

p4

/ », Ut amp; major quam

l n, Prxterea, quoniam l n maj.or eft quam x, ft fuerit x

major

, at minor quana

-ocr page 169-

iE Q_ V A T I o N V M. nbsp;nbsp;nbsp;141

major quam », erit necefl'arió inter hos terminos l n Sc n. Quód fi veró » fneritvelaequalis vel major quam at, quia/x^-f.nbsp;«^.vmajuseftquam/)'*, critamp; majusquam Scx

major quam nbsp;nbsp;nbsp;. Acproindequslibet radicum xquationis

propofitae major erit quam minor horum terminorum n 8c , at minor quam/ ».

C A P V T X.

7)e limitïbus t^^quatiomm quatuor dimenjiomm, in quibus nullus terminus deejl.

Tro^. I. nbsp;nbsp;nbsp;mmxx

T) Er tranfpofitionem eft/at^ nbsp;nbsp;nbsp;00 ar‘' ?w7»A*A; /gt;'’, ideo-

que/A?’a; majas quamA?**, amp; /ATA w’majusquam x^. lam fi fucrit propofitaasquatiorealis,. eritamp; Arrealis, amp;vel2-qualis vel major vel minor quam ». Quod fi fuerit «equalis velnbsp;major , erit Ixx nxx majus quam a:^, hoe eft, l n majornbsp;quam x,8c x minor quam n. Multó igitur magis minor erit quamnbsp;/ ». Ergo X neceflarió minor erit quam / ». Deinde ex ea-dem aequatione /a^ m^x co a'* mmxx-^p‘* conftat, eflenbsp;Ix^ n^x majus quam p\ Sedinventaeft / » major quamx»nbsp;ac per confequens / / » » 2 / » majus quam A A,amp; /’ a; 4- /K » Anbsp; 2//«A majus quam / Ah Quare erit/*a Ihhx llnx

«* A majus quam amp; a major quam nbsp;nbsp;nbsp;

quandoquidem cubus ex / » major eft quam l n n -4-2 //« 4_ «3multó magis erit x major quampiquot;* divifum per cubum ex / «. Inventus eft itaque terminus unus major amp; alter mi-nor quam unaqusque radicum ajquationis propofitae, five haecnbsp;duas five quatuor radices habuerit. Prsterea , quoniam inveni-mus, quód / « Temper major eft quam A, fiponatur a quo»*nbsp;que major quam »; manifeftum eft eam efle inter duos termi-aos / -J- » amp; ». Qiiódfiautem a fuerit aequalis vel minor quamnbsp;quoni^n eft/a* -f* »* x majus quamerit /»»a »*a

S j nbsp;nbsp;nbsp;majus


-ocr page 170-

I4^ nbsp;nbsp;nbsp;De Limitibvs

majus nbsp;nbsp;nbsp;ideoque x major quamnbsp;nbsp;nbsp;nbsp;. Ergo unaqvix-

queradicumpropofitsarquationis, fivedtias, five tres habuerit, major erlt quam minor horum duorum terminorum» amp; ^—-^7-»nbsp;at minor quam/-}-«.

1'

^rop.i. AT'*—Ix^ mmxoo o.

Per tranfpofitioncm efï mm x x -{- n^x -i- nbsp;nbsp;nbsp;co Ix^ —x^f

ideoque l major quam x. Similiter eft -f-;gt;r p‘* co Ix^

»w»?x;v,acIdcirco ar major quam Pr»tereaeftA’‘‘ /w»zar.v

p‘'CO ixquot;^'n^Xy ac per confeqitens arXmajus quam . De-niquc eft x*-\~mmxx «’ xzolx^p*y amp; confequenterxï major quam^ . Qiiare invenimus, unamquamque duarumra-

dicum aequationis propofitsemajorem eflequam^jy'^ , amp;

YC.^ y atminorcm quam/.

^rop.Ix^mmxx'rigt;X’\-^'^ co o.

Per tranfpofitionem ed Ix^ m m xx X CO AT^ ideoque Ix^ -4- mmxxnbsp;nbsp;nbsp;nbsp;X majus quam xquot;*. lamfi propo-

fita scqiiatio fuerit realis, erit xfealis, amp; vel sequalis vel major vel minor quam maxima duarum m S^n. Quódfi fueritïqua-lis vel major, erit/x’ »?x5 «x’ majusquamx'*, amp;/-4-»^nbsp; » major erit quam x, amp; magis fi fuerit x minor quam maxima duarum m Sc n. Qiiare l -^m « erit neceflario majornbsp;quam X. Prïterea m erit aut gequalis, aut major , aut minornbsp;quam». Qiiod fi fueritOErqualis aut major, amp; quidem x majornbsp;quam m , erit radix sequationis propofit$ inter hofceterminosnbsp;/ m nScm. Quód fi , exiftente m tequali aut majore quamnbsp;«, etiam m fit tequalis vel major quam xj eritamp;

-i-ff’a;

-ocr page 171-

iEQ_VATIONVM. nbsp;nbsp;nbsp;ï^j

X zqualc aut majus quam /-j-m xxx, ac per coiifequens majus quam ideoquc x major quam

nbsp;nbsp;nbsp;^ aequalis vel major quam »,

crit X neceflarió maj®r quam minor horum duorum terminorum

^ ^ / nim mi 4- «3 ’ ^ ” fucrit major quam m, confimili ra-tione demonllrabitur x etiam neceflarió majorem effe minore horum duoruni terminorum » amp; „ _pnbsp;nbsp;nbsp;nbsp;Invenimus

ergo unamquamque duarumradicum £Equacionis propofitsma-

, n

joretn efle minore horum terminorum m Sc -p .------;—¦

/ W W-}- nbsp;nbsp;nbsp;-f- «3

vel aequalis vel major fuerit quam « ; aut majorem minorc

duorum » amp; -j—,———^--, fl « major fit quam w : at veró

inn-{-mmn ni nbsp;nbsp;nbsp;/nbsp;nbsp;nbsp;nbsp;inbsp;nbsp;nbsp;nbsp;¦»

femper minorem quam

‘Projfgt;.4. AT'»—Ix^mmxx n^ nbsp;nbsp;nbsp;CO o.

Per tranfpofitionem eft Ix'^ mm xx co x‘* ideoque Ix^ mm xx majus quam aquot;*, amp; lx mm majusnbsp;quam^: A. lam fi fuerit propofitaïqiiatio realis, erit amp; a realis^nbsp;amp; vel xqualis vel major vel minor quam m. Quód fi fuerit as-qualis vel major, erit lx-\-mx majus quamxA, Sc / «/ major quam a ; amp;multómagis, fi fuerit a minor quam/». Ergo anbsp;neceflarió minor erit quam l-\-m. Vndefi fuerit a major quamnbsp;erit inter hofce terminos m Sc m. Quód fi x tuerk velnbsp;*qualis vel minór quam w, quandoquidem amp; Ix^ mmxxnbsp;*najus eft quam pquot;» erit Imx x-i~mmxx majus quamp^j idco-

que A A majus quam nbsp;nbsp;nbsp;^ major quam /nbsp;nbsp;nbsp;nbsp;.

Qpare quslibet duarum radicum asquationis propofita: major quam minor duorum terminorum mScynbsp;nbsp;nbsp;nbsp;mi-

iVorquamZ w*.

Tro~


-ocr page 172-

144

De Limitibvs

^ro^. 5'. nbsp;nbsp;nbsp;—n^x~\-p^ co o,

Demonftrabitur extranfpofitionibus requifitis x fore majus quam x*y ideoque «majorcm quamarj amp; n^x majus quam/A;*,

ac proinde ^ majus quam afA:; amp;dcniquc majus quamp^,

amp; per confequcns x majorem quam ^ . Invenimus itaque tcr-

minum unum majorem fingulis radicum acquationis propodtar, at veró duos alios minores.

lPr^.6. x^’\-lx'^mmxxx pquot;^ co o.

Per tranfpofitionem Ammxx-^n^x^ x'^ l x^p\ ideoque mtnxx-^n^x majus quam x^, amp; mmx -f- «’ma/usnbsp;quamarb lam fi fueritpropofita aequatio realis, eritA;realis, amp;nbsp;velaequalis vclmajor vel minor quam n. Quód fifucrit aiqualisnbsp;vel major, erit mmx nnx majus quam , Scy^ mm -^nnnbsp;major quam at; amp;multómagis, fifuerit at minor quam». Qua-reerit Ymm nn fempcr major quama:, amp; a; erit inter termi-nosYmm nnamp;», dmajoreftquam». Qubddfueritatqualisnbsp;autminor quam», quoniam eft mmxx-\-n^x majusquamp'*,nbsp;erit quoque mm nx n^x majus quam pquot;*, ideoque a: major

quam -^ nbsp;nbsp;nbsp;. . 'Ergo qutelibet duarum radicum acquationis

propodtac major erit quam minor horum duortimtexmiuorum»

„6 nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;Vnbsp;nbsp;nbsp;nbsp;/-

« —, atminorquamy mm-\-nn.

^rop.j, x'^-y-lx^mmxx-^n^x^p‘^'j:gt;o.

Fadistrahfpodtionibus requidtis, demonftrabitur efle a; mino-rem quam m amp; nbsp;nbsp;nbsp;, at majorem quam ^.


-ocr page 173-

u£q_vationvm. nbsp;nbsp;nbsp;145'

Tro^.Z.x'^Ix'^-{-mmXXngt;x—p* od o.

Pcrtranfpofitionem eftAr**—lx'' GO n'x-^-p*—mn-xx^xé^o-que fi fueric 00 lx', erit xZD ly amp; /»’ 00 n'^x, Scn' x -{-p*

mm

TXi mmxX, acproinde/«5 nbsp;nbsp;nbsp;zomm xXy^ xCO ^nbsp;nbsp;nbsp;nbsp;-

Vndepatet, fifuerit /00 ^ nbsp;nbsp;nbsp;-¦, hoceft,fihabeatur//»7K?

00/radicem a:quationis propofitje fore asqualêm fin-gulis terminorutn asqualiiim IScylidcirco , fubfti-

tuto in boe cafuin jequationepropofica valore ipfuis/)'*, nempe llrnmIn', ipfamefle divifibilemper x-r-l. Quód fifuericx‘*nbsp;niajus quam/AT^, boceft, at major quam/, erit quoque a; ƒ)“*'nbsp;majiis quam mmxx\ amp; fi fuerit / ar^majus quam x^, boe elt,nbsp;I major quam Xy erit amp; mmxx majus quam n' x -{• ƒgt;'*. lamnbsp;quandoquidem arquatio propofita eff realis, erit xrealisamp;velnbsp;atqualis, vel major, vel minor quam y!gt;. Quódlïfuerit Jequalisnbsp;vel major quam/), fitque major quam/, quoniam tunenbsp;quoque majus eft quam mmxxyx:ntamp;Ln'x-{-p' x majus quam

mmxXyS^ nbsp;nbsp;nbsp;majus qudmAT. Ergo in boe cafu erit ar major

quam /, amp; minor quam nbsp;nbsp;nbsp;• Quódfiautem xminoriexi-

ftente quam l, ipfa fit squalis vel major quam p , quoniam 8c tune n'x-{-p‘* minus eft quam mmxxy erit fimiliter n'x^p'x

minüsquam mmxxy amp; confequenter —minus quam^'. Igitur in boe cafu erit x minor quam/, amp; major quam ”*

Quare univerfaliter apparet, tequationem propofitam non ba-^cre pratter unam radieem realem ipfi/aequalem, cum eft//»?»?

modó qucelibet radieum, fiveunam , fivetresba-ttterit, fuerit Temper neceflarió inter maximum amp; minimum

ïriumterminorum /, nbsp;nbsp;nbsp;, 8c y”

* mm * f

mm

T?rop.

II.

-ocr page 174-

14^ De Limitibv s

Trop. 9. nbsp;nbsp;nbsp;—Ix^ mmxx n^ X'^^* zo o.

Per tranfpofitionem cft x'* — Ix^zop*—mm x xx, ideo-quefifueritzO Ix^, hoe eft, xzol, eritmmxxzo — n^x /gt;“,


amp; per confequensmmxx CD— »’ Z pquot;*, amp; a: at X

X ZO nbsp;nbsp;nbsp;. QuódfiergoZsequalisnbsp;nbsp;nbsp;nbsp;, hoe eft,

fi fuerit llmmzOpquot;' —In^radix sequationis propofitxa:quaIis erit unicuique terminorum xqualium / amp;nbsp;nbsp;nbsp;nbsp;• ideoque ft

in hoe cafu in sequatione propofita loco pquot;*, fubftituatur ejus valor, nempe, apparebit ipfam dividi pofle pernbsp;X — /, atque nullam aliam radicera veram admittere praster /.nbsp;Si veró xquot;quot; fuerit majus quam / a;^, hoe eft, a; major quam /,nbsp;eritamp;p‘^majusquarn«z»?A'A' »’x; amp; contra, fi fuerit / major quam a:, eritetiam mmxx-\^n^ x majus quam p^ lamfiat-quatio propofita eft realis, eritA-realis, amp; vel squalis, vel major, vclminor quam «. Eftoigitur, quód at major quam/fit velnbsp;atqualis vel major quam »j quarecumamp; pquot;* tune majus fit quamnbsp;mmxx-^-n^ Xy eritquoquep”*majus quam mmnx-\-n^x'y ideoque —— majus quam x. Quare in hoe cafu erit x majornbsp;^ mm n-f-ni 'nbsp;nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;'

quam /, amp; minor quam nbsp;nbsp;nbsp;. Qupd fi x, cüm major eft

quam /, minor fuerit quam», eritamp; p** majus quam»» at ^-4-n^Xy ideoque multó majus quam mmx x-\^nn x x y amp; confe-

quenter nbsp;nbsp;nbsp;majus quam at a?,amp;nbsp;nbsp;nbsp;nbsp;major quam x-

Quare in hoe cafu x erit major quam /, amp; minor qukn

y nbsp;nbsp;nbsp; Quod fi vero a-, cüm minor eft quam /, vel squalis

fuerit vel major quam », erit mmxx-^-n}x majus quam p*t ideoque mmxx^nnxx majus quam p^, amp;a'a;majus quam

^ major quam / nbsp;nbsp;nbsp;. Ergo in boe cafu erit a?

minor


-ocr page 175-

iE Q„ V A T I o N V M. nbsp;nbsp;nbsp;147

minor quam /, amp; major quam -j/ —. Poftremó, cum;^

minor quam/, etiam ipfa minor fit quam «, erit m x xx majüs quam ƒgt;“*, amp;nbsp;nbsp;nbsp;nbsp;a; mulcó raajus quam/»-», amp; per

confequens x major quam

Igiturxinhoc cafu, mi

f4

nor erlt quam/,amp; major quam

^ mmn

Quïcumitafint, conftatuniverfaliter, «quationem propofi-tam non habere nifi unamveramradicem, qus jequalis eft ipfi/, quando eft llmmCDmodo unaqusequeradicum, fivenbsp;unam tantum, five tres habuerit, fuerit Temper neceflario inter maximum amp; minimum trium terminorum /, —_ amp;

’ mmn ni

Y_?!__

wm-4-ttit ‘

^roj’. 10. nbsp;nbsp;nbsp;—mmxx — n^Xzo o.

FaftisneceflTariistranfpofitionibus, demonftrabitur, quód x major eft quamDeinde erit quoqueger tranfpofi-lionem lx^mmxx-\-n^x-{-p* ZOX*, 8c per confequens/x*nbsp;'-^mx^’^nx^-\-p^^ majusquam x*, 8c l-\-m K p major quam x. Porró, quoniam eft x'* OO / x^-Ym m x x-j-»3 x-|-;gt;%nbsp;^ritx4 majus quam /x^nbsp;nbsp;nbsp;nbsp;xx, amp; x x majus quam lx-\-mm^

ideoque mul to magisx major erit quam Y8c Ylm-{-mm. ^irniliter, cum x^ major fit quam/xx-4-»«zwx-|-k^, erit mul-to magis major quam nbsp;nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp;8^^lmm

amp; fic de reliquis terminis, quosfubftitu ere licet loco x’, nainores quam xh Sic x'^ majus eft quam /•* »“* «4 ^ quamnbsp;amp; fic de reliquis. Prsterea, quoniam x major eftnbsp;SlUam « amp; ƒgt;,amp; /x^nbsp;nbsp;nbsp;nbsp;w /w X X ff ^ X •4-p^00x^gt;erit l x^-^m m xx

ff ff X X -{~ppxx majus quamx'*,ideoque/x mm-^n ff pp J^ajus quam XX aliqua quantitate, qusequidem quantitas, etiam-t fit incognita,fi appelletur a, ?,,habebitur /x -f- ff? w? ff ff -j-pnbsp;3C) XX -J- Quantitas autem haec incognita xt x. neceffario mi-*^tgt;r erit quam»?»?-4-»» /gt;/’,alias ,ablatisex duabuspartibusnbsp;*^naiionis praecedentis, «equalibus, aut minori quantitate ex pri-

T 2 nbsp;nbsp;nbsp;ma

-ocr page 176-

148 nbsp;nbsp;nbsp;De Limitibys

maamp; majoriexfecunda, efletreliqua/^tautsequalis, aut major quamara*. Qiiodforet abfurdum, quandoquidem ar demonftra-taeftmajor quam/. Quarehabemus hancsquationem xxzolxnbsp;— 5,;c, qu$ erit realis , eritquex OO

y -^-mm nn pp. Manifeftum veró eft, quodi J^nn-^pp majuseftquamJ:// »^wï — x,?,. Ergo | / ^y^lij^mm nn pp major erit quam x , ideoqiienbsp;m m-^nn pp multo magis major erit quama;-; itautnbsp;radix propoficse squationis neccflarió fit inter y i lnbsp;nbsp;nbsp;nbsp;mm Sc

yi-^mm nn pp.

^rop.w. x‘^Ix^mmxx-\~n^ Xp*zoo.

Pertranfpofitionemefta:**—Ix'^—^mmxxZDp^x. Vn-de,fifueritarquot;^—Ix^ —mmxxZD o, hoe eft, omnibus per aquot; ar divifis, XX—lxGO o, eritquoque—n^xzoo. Hoe

eft, fifuerita-ar GO lx-{~mm,yt\ x GO^V 'y/-Jl 4- ?» w?5 erit amp; /gt;‘*G0«’ar,vela-C0^- Quareconftat,lifiierit ^ ZO^-i-y{U mm,nbsp;radicem jequationis propofitse fore requalem fingulis termino-rum requalium ^ amp; i/ y” yi mm. Quódfifiieritar^ma-jus quam lx'^-\-mmxx^ hoe eft, ar ar majus quam lx-\-mm‘, eritnbsp;p^ ctiam majus quam ar, hoe eft, ^ majus quam ar. lam exH

ftente x x majori quam / xm m, erit xxoDlx-j~mm plus ali-qua quantitate. Qus quidem quantitas , etiamfi fit incognita» fi roceturcer habebitur ar ar GO/ar aüTJ^i-l-^:;?,, amp; ar GOnbsp;y\ll mm z.z., eritqtie ar major quam ^ / yyi mfif-Quare in hoe cafu erit ar minor quam ^nbsp;nbsp;nbsp;nbsp;amp; major quam j ^ “1quot;

yyïy: mm. Qubd fi fueritarquot;^ minus quam ar ar, hoC eft, ar ar minus quam l x-gt;rmm\ erit minus quam»’ar, h°‘'nbsp;eft, armajorquam~ . Hitrcexiftentearrfminoriquam/ar

erit

-ocr page 177-

gt;Eclvationvm. 149

crit^f Aroo lx m m minus aliqua quantitate. Qiiae fi nominetur K.a, habebitur x x quot;X) I x mmz.z.i hoc eft, x 00nbsp;Y ill-¥»tmZ.Z., eritque x minor quam i/-f. -y/

Ergo in hoe cafu erit x major quam^ , amp; minorquamj/4[-\ll-¥mm. Quare univerfaliter patet , radicem ^quationis propofitjesequalemefl'eipfi^nbsp;nbsp;nbsp;nbsp;quando^

aquaturipfi-tZ q/Sin fecus, quamlibet radicum, five unam tantum , five tres habuerit, lemper efle inter hofce

Trop.ix. x‘^-\-lx^-\~mm!gt;cXn^x—^ zo o.

Per tranfpofitionemeftx'*—00 x—/x’—«fxx jideo-que fi fucrit x ZO p, erit quoque w’ x 00 l x^-\-mm xx, amp;

X 00 nbsp;nbsp;nbsp;^Vndeconftat,nbsp;nbsp;nbsp;nbsp;ajquetur , radi-


cem squationis fore aequalem fingulis terminorum xqualiump amp; —. Qiiod fi fuerit x* maj^us quam p* , hoe eft , x major

quamp, erit quoque «^x majusquam/x’ »i wxx. lam fiae-quatio propofitaeft realis, eritamp;xrealis, amp; velaequalis, vel major, vel minor quam m. Quöd fi fuerit squalis vel major quamnbsp;amp;eademquantitas xetiammajor fitquamp, quandoquidem.nbsp;amp; tuncn^xm3juseftquam/x^ *^^'^-^gt; erit»5;i-i-najusquam

lmxxA~mmxx,èc ,—— majusquamx. Quare in hoe cafu 'nbsp;nbsp;nbsp;nbsp;Im mmnbsp;nbsp;nbsp;nbsp;^

erit X major quamp, amp; minor quam ^ ^ nbsp;nbsp;nbsp;• Quödfi exiftentc

*¦ majore quam p ipfa minor fit quam/»j erit x majus quam lx^ mx\ Si majus quam xx. Ergo in hoe cafu erit x

major quam^, amp; minor quam Y nbsp;nbsp;nbsp;fi vero , x minori

exiftente quam ipfa fit major quam m, vel eidem sequalis, quandoquidem amp; tune«^xminnseftquam lx ^mm xx, erit n^x

T 3 nbsp;nbsp;nbsp;minor


-ocr page 178-

150 nbsp;nbsp;nbsp;De Limitibvs

minorquam/A;’ /WA:’jhoccft, irjï-majusquam. Qtiare in hoe cafu erit at minor quam^gt;, amp; major quamnbsp;nbsp;nbsp;nbsp;. Detii-

que, cüm fuerit x minor quam/», amp;ipfaetiam minor quam «?, quoniamamp; tune a;minuseftnbsp;nbsp;nbsp;nbsp;-{-mmxx,tï'\x.n^x mi~

ï\\isc^h'almxx-\-mmxx^ amp; a: major quam —. Vndc conftat univerfaliter, radicem jequationis propollts eilè Jequa’?nbsp;lem fingulis terminorum squaliump amp; /j-gt; cüm eft Ipp

mmp ajquale ipfi fed cüm injequales funt, eflè radicem£e-quationis propofits neceflario inter majorem amp; minorem termi-

norum

ni

gt;» * lm mm‘

*Pro^. 13. nbsp;nbsp;nbsp;x—co o,

Faftis neceflariis tranfpofitionibus, demonftrabitur x forc minorem quam/», j/ C ^ nbsp;nbsp;nbsp;^^ i at veró majorem quam

Ipp mmp-{-n*

‘Prop.i^. x'^-^lx^mmxx—x ix) o.

Per tranfpofitionem eft at'* — n^xZO mmxx-\-p‘*Ix^ jideo-

que fi fuerit Ar'* CO a;, hoe eft, a; CO », erit «zAT a: /»“* 00 /Ar^, hoceft, .—3Q x^. Quod ft fuerit AT major quam «, eritamp;

mm a; AT p‘t naajus quam /a;’ ; fin minor fuerit, crit w a; at minus quam/at^ lam, fiAA major eft quam «, amp;etiamvel jequa-lis vel major quam/», quandoquidem amp; tunc»zi9ZA'Ar /»‘*majusnbsp;eft quam/at^, multomagiserit»zwzArA; p/» ATArmajusquam/Ar’,

hoe eft, —quot;^^^majus quam x. Ergo in hoe cafu erit at major

quam «, amp; minor quam nbsp;nbsp;nbsp;^ Quód fi x major fuerit quam

«,amp; etiam minor quam/», quoniam amp; tune wzzwA’x p-'majus eft quam Ix^, erit quoque mmpp -\-p'^majus quam /at^, hoe eft,

minor quam nbsp;nbsp;nbsp;minor quam y C. PIPLPP_±£1,

Quare


-ocr page 179-

jEQ.VATION VM. nbsp;nbsp;nbsp;15-1

Quare in hoe cafu erit x major quam « , amp; minor quam

Y C. nbsp;nbsp;nbsp;. Quod fix minor fuerit quam «,amp; velaequalis

vel major quam^, quandoquidem amp; tune mmxx-^p'* minus eft quam/x^, eritquoque?»»»ƒ)/) /gt;''minusquath /x’,amp;xmajor

quam Y nbsp;nbsp;nbsp;—. Ergo in hoe cafu erit x minor quam »,amp;

Wajor quam Y nbsp;nbsp;nbsp;• Quód fi verö x minor fuerit quam

»j amp; ipfa etiam minor fit quam p, quoniaRi amp; tune mmxx *ninor eftquam/x^; eritquoque«?«?xx-[-yt»pxx minusquam

/x’, amp; nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;. minus quam x. Quare in hoe cafu , erit x minor

qnam n, amp; major quam nbsp;nbsp;nbsp;. Vnde univerfaliter apparet,

^adicem Eequationis propofuï neceflarió efle inter maximum amp; Minimum trium terminorum «,-j~^f amp; y C. —^

15:. nbsp;nbsp;nbsp;—mmxxJ^n^x

Per tranfpofitionemeftx'* /x5 — mmxxcop^*n^x; ideo-qüe fi fuerit x4 /x’ — mmxxZD o,feu,divifis omnibus terminis per XX, xx-4-^^—30 o; eritquoquepquot;* — k^atgo o,

Weft,fieftXX XvelX 00 — i/ -|/T77 ww

^«tp‘t3Q„3;^^feuxX^ • Vndepatet,fi^ eftaeqiialeipfi—i/4-Vradicem xquationis propofitae efle ^qualem fin-gulisterminorumaequalium^ amp; nbsp;nbsp;nbsp;Quód

fueritx4-y./x^ majusquam mmxx^ hoe eft, xx^f~/xmajus Sinam m m,ent quoquemajus quam x,hoc eft,^ majus quam

^¦Ac proinde cum xx /a: majus fit quam w»?,eritxxHh/.*'majus quam mm aliqu a quantitate. Quantitas autem hsc,licet fit incogni-^2,vocetur.t.t„eritque xx /xoo»gw 2:2L,feu xxqo—Ix mm zz^,nbsp;eftjA^x —nbsp;nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp;ideoqucx major quam

Y nbsp;nbsp;nbsp;Ergo in hoe cafu X minor erit quam ^ amp;

**^®jorquam — i l-\-Y nbsp;nbsp;nbsp;Quód fi fuerit x^ Zx’minus

-ocr page 180-

I5^ De LiMITIBVS iECLVATIONVM. nus quam mm xXy hoe eft, ar a: / ar minus quam w »/, erit quo-que/)‘'niinusquam»’Ar,hoceft, ar major quam^ . Hinc cum

arx /arminus fitquammm, cntxx-\-lx minor quam mmali-qua quantitate. Vocetur quantitas hïc quamvis incognita tz.y eritque ar ar /ar COnbsp;nbsp;nbsp;nbsp;vel ar ar OD —Ix mm — 5,2:,hoc

eft, ar CD — { / Y ^11 mmz.z., ideoque ar minor erit quam ^ll-\-mm. Qiiare in hoe cafu erit ar major quam ^ ,nbsp;amp; minor quam —nbsp;nbsp;nbsp;nbsp;Y^-^rmm. Atqueita in genere per-*

fpicuumeftjcum^ requaturipll-—'Y-YY nbsp;nbsp;nbsp;,radicem

./ gt;/ a/Z-h/ww.

sequationis propolitae requalem elfe fingulis terminortim requa-lium^^ amp; — i/ yi// ^/*r»;rinminus, quamlibetradicum, five unam tantum, five tres habuerit, neceflarió efie inter hofcenbsp;terminos^

FINIS.

-ocr page 181-

J o H A N N I S DE W I T T

ELEMENTA

CVRVARVM

L I N E A R V M.

Edita

Oper^ Franci§ci a Schooten^ iu Academia Lugduno-Batava Matliefeosnbsp;Profefïbris.

tA M S T E L O D A M ly

ïxTypqgraphia Blaviana, mdclxxxiil 'nbsp;nbsp;nbsp;nbsp;Swn^tibm Societatu.

-ocr page 182- -ocr page 183-

ClariJJlmo^ ^oBiJJlmoque Viro,

D“. FRANCISCO a S CHOGXEN,

lOHANNES DE WITT

S. P. D.

Inearum reBarmn-, angulorum-^ qm, quos com^rehendunt^ut ^nbsp;\jigurarum reBilinearum, quanbsp;inde nafcuntur, nee non Qïreu^nbsp;lorum naturam 'veramatque in^nbsp;trinfecam ^frofrietatefque^ra^nbsp;cifuds^ meo quidemjudicio^fatisferfpeuè tradi-derunt Anttqui^ ac quo -paBo ex ïifdem traditis,nbsp;imo ex -pau cis frinci^alioribus eorundemnbsp;^rincipiis, qualibet Problemata Plana^ aegene^nbsp;raliter quacunquein line arum reBarum, angu-lorum-, jigurarumque reElilinearum-, nee non Cir^nbsp;eulorum eontem-platione Qp cognitione defidera-ri queunt, refol'vantur atque eruantur, uniuer^nbsp;fali quddam neid ÊT Methodo Analjticd, pernbsp;^quationum innoentionem, harumque rejblutio-nem,pleniusplaniufque d Reeentioribus oflenfumnbsp;i Adeb ut vel unieo Circulo dato, utut exiguonbsp;aut ingenti, quaeunque Problemata Plana pernbsp;folas line as reBas unufquifque,in diBis Antiquo^nbsp;irum Recentiorumque Geometrarurn paceptisnbsp;mediocriter verfatm ,facillimè refolvat j aepro-

V 2 nbsp;nbsp;nbsp;inde

-ocr page 184-

mde de ufdem'velflura vel alto moda- fro-pojïta aü demonftrata quadam dejtderars, (ff fitfer-'üüLCUum ^ ineftum femfer exiflimarui. At 'veto cum QMerarum linearum cuwarum Elemen-ta^frout A ?terihm tradita atque d Recentiori-hm exflicata funt^diligentius conjtderajfem^ori-gtnemeamm è folido feti atque inde ipfas in ¦planum transferri naturali ordini, qui in Aiathe-maticis qmm maxime ohfewandus efl, omninonbsp;contrarïum duxi; qmmadmodum Qf demon-firationes in ufdem Elementü frofojïtm, midtisnbsp;in locis eadem de caaJaQf frofter -varias ratio-num compojitiones, qmbm/kpe innitMntur^ fub-obfcurm-, ac longa Propofiüotmm firie Le3ori-hm t^dio memoruque oneri e^e judicarvi. Atquenbsp;ed quïdem contemflatione excitatmjampridem,nbsp;dum ftudiis humandoribm Liberaliumque Ar-tïum doBrinoi incumbere mihi otium erat^ anim-ad'verti, non eas folum, quas 'uulgo Coni fe-appellarunt j/èd ^ omnes omnino cur-'vas tineas^ cujufcunque fint generis, multiplici-ter quidem ex 'varia corporum dvverfimodè com-pofitorum autfilt;puratorum feBione gigni, at 'veto earundem fingulas infinitis quoque mod is mnbsp;planogenerari, ipjdrum autem naturam ^pro^nbsp;prietates ex ea generatione multh facilius qudmnbsp;ex corporum feBione deduct^ acfirmiter mihiper-fisafiumhabeoy nuUum aliam ejfe cmfam, quqd


-ocr page 185-

linearum cuwarum fecundigeneris ulteriormn^ ^^egraduum ortus, natura, frofrietas ^atquenbsp;^JJentia, cum exa3aJpeciermn enumeratïone, dnbsp;nemine antehac expUcata ac demonftratanbsp;qtidm qmd tam in traBatione ortm ^^genera~nbsp;^ionis j qudm in demonflratione ejfenti^ acfro-TBetatum linearum curnjarum frimi generis dnbsp;^aturali fimflicijfima •via dejïexum fit, ut~nbsp;fote cum earundem eontemflatio ,^rout inflanonbsp;fim-plicijjtmè ^ quidem di^verfimode gener an-, inteÜeBum Qf imaginationem ad genejtnnbsp;linearum cuwarum fecundi generis quafi ffontenbsp;^^cat. Cumque eorum t qua antehac dum'^ernbsp;^tium licuit:, eo/peBantia meditatus fumpA nmiQnbsp;amicijjime Schooteni, co^iam tibifieri defidereSynbsp;en, quantum in me efi, dejiderio tuo fatisfacio,nbsp;quaque de eodem argument o d me quondam con-f^riptay ac fgt;enein ordinem redaB'a invent, jamnbsp;^ihi mitto, tuique omnino juris fado, cater a au-qua ff ar firn tantum annotata funt^fi rnodonbsp;amp;aviora id ferent negotia, recolligam, debito-or dine conjungamj recolleBa^atque ordinatanbsp;quo que temp ore tihi miffurm^ p^ale. Haga:nbsp;gt;0%. VIII OBobr. Annï M. DC. lviil

Vs

J o:

-ocr page 186-




-ocr page 187-

i;9

J O H A N N I S DE W I T T

ELEMENTA

CVRVARVM

L I N E A R V M.

L J B E R F R I M V S.

C A p n T I. DEFINITIONES PRIM-Ê

1 per re(5lam lineamimmotam altera reda certo fui punftofibilemperpa-rallela moveatur aut incedat, eodem-que illp motu anguli cujufdam redtiii-nei, circa pun(5lum fixum (quod idemnbsp;(ït cum ejus vertice ) circulariter mo-bilis, crus unum femper per praedi-^um mobile punftum tranfiens fecumducat, atqucitanbsp;fimul cruris alterius, amp; diftas lineas incedentis interfe-¦^ione curva defcribatur linea; reda, quae, uti praediftuminbsp;, fibi femper parallela movetur aut incedit, Defiri-®lt;?«J-dicetur.

II-

. Altera verb refla, immota manens, ^ireBrix voca^* ^tur,

HL

Praedidtus autcm aiigulus re(flilineus, atque is qui ei deinceps, Angulorum mobïlïum nomine venient.

IV.

-ocr page 188-

HÖO nbsp;nbsp;nbsp;El EM. CuRVARUM

IV.

Al (\\xos deferibens ad direBrkem efficit, Anguliad ^ire£iricem diceiitur.

V.

Punélum fixum, circa cijyi.oêi.angttUis mobilis circulari-termovetur, Vo.kr nuncupabitur.

Vï.

Ea autem defcribentk pars, quae inter Tolum amp; dire-^ricem intercipitur, Intervallum nominabitur.

VII.

Crus anguli mobilis, quod defcribens fecum ducitjO*/^ • lattens.

Vin.

Altcruniverócrus, quod a nbsp;nbsp;nbsp;fecatur, Crus

Efficiens, amp; per anguli verticem produiftum, nbsp;nbsp;nbsp;Effi-

ciens appeilabitur.

IX.

Cum defcribens'Eolum tranfit, ac proinde amp; cuni crurepattente coïncidit, efle tam deferïbentem quamnbsp;crus pattens, ut amp; Itneam efficientem totumque angulwittnbsp;mobtlem inflationeprima conftitutum dicemus; ac quo-ties de iis fimpliciter fermo erit in tali ipfaspofitione con-fiderabimus,

'X.

Qiiamlibetcurvam, interfeftione, utipriediftumeftgt; in piano genitam, defcriptam dicemus, efficiënte atquenbsp;intervdllo confideratiS, ut exhibentur ac fibi inviceninbsp;junguntur inftationeprima ; adeb ut efficiens cum inter'nbsp;quot;vallo, quod tam cum ipfa defcribente quam cum crurênbsp;patiënte in eadem ftatione coïncidit, anguhmmobtlernnbsp;utrinque conftituat.

Vc

-ocr page 189-

Lib. I. Cap. I. nbsp;nbsp;nbsp;i6i

Veinappofitisfiguris, firedaHG (Ibifemperparallelacerto fuipunéto, putaH, movericoncipiaturpenjpmotam EF, eo-demque illo motu fecum ducere crus B H aoguli H B G, circa-

-ocr page 190-

Elem. Cvrvarvm

lariter mobilis circa punfium B; ita ut idem crus B H femper tranfeat per prsec^um ipfius HG punéium H, fimiilque alte-riiis cruris B G ac didse lineae H G interfcdione G defcribaiurnbsp;curvalineaBG: eruntnbsp;H G defcribens. .

EF direbirix.

H B G, H B P angptli mobiles.

F H G, E H G angnlt ad direllricem.

B ^oIhs.

BD mtervallum.

B H cruspatiens.

B G crus efficiens,

P G Unea efficiens.

D Kdefinbensinftationeprima, fivede/cribensCimplicker. DBC,DBAangabmobdes in flat tone prima.

A C efficient in fiatione prima, üve efficient firnplici ter.

i.

Curvam B G, efficiënte A C, intervallo vero B D dcfcriptam di-cemus •, Et apparec, cüm efficient P G eft in ftatione A C, crus patiens B H coïncidere cum intervalloB D;ac défcribentem H G tune efte in ftationeD K, atque per efficientem amp; intervallum conftituinbsp;utrinque angstlos mobiles D B C, D B A.

Theorema I.

7ropofitio I.

(^lalibet efficiënte, amp; quocu nque intervallo, angtiU mobiles sequales fintiis,qui ad dire^iricem funt ab eadertinbsp;parte, ciirva defcripta, hoeipfi propriumerit, urquïC'nbsp;vis refta a qnolibet curvse punfto ad defcribentemeffinbsp;cienti aequidiftans applicata poflït reftangulum, fub iü'nbsp;, tervallo atque ea defcribentis parte, quae inter Tolu0nbsp;amp; applicatam intercipitur, contentuni.

Sit effixiente ABC, intervallo BD , amp; direÜricefL Fdefcripf® curvaBG; itautnbsp;nbsp;nbsp;nbsp;wofó«DB,AfitatqualisanguloED®

ad direElricem, fitque a pundo G in curva utcunqne aflumpto^-d defenbentem D B K applicata reda G K efficienti A C parallels •nbsp;dico quadratum applicatac G K redangulo D B K squale efte.

-ocr page 191-

i6j

Lib. I, C A p. I.

Conftitutis enimtam mgulo mobilio^\m defcrihente inftatione Utifuere, cumper ipfarum interieftionem defcriptum eft pun-lt;ftutn G, veluti inHBGamp;HlG:fi tam mgttlHs mobilis quatn is


-ocr page 192-

1^4

Elem, Cvrvarvm

gt; perCor. quiad direBrkem cftreftusfit, uti in prima figura, erit 'ut Hl ’Ig' ad IB,itaIBadlG, ideftS utDB adGK, ita GKadBK.

1 per ^4 ac proinde ^ quadratum refl:* G K reótangulo D B K aquale primi. erit.

^ nbsp;nbsp;nbsp;Atverofiobliquusfuerit uterqueangulorum AB D, EDB,

^ nbsp;nbsp;nbsp;’ utiincxterisfiguris, kcsbunt kie efficiens dc dtreilrix iproduamp;X

‘iper z9 primi.

5 per 6 primi

bus.

^in ca-fib. fig.

III nbsp;nbsp;nbsp;8c

IV nbsp;nbsp;nbsp;,autnbsp;limiii-bus

ad eas partes, ubi mgulns mohilis, isque qui ad direBricem eft, acu-tierunt. fititaqueipfaruminterledioin Lpunéto. Quoniam igi-tur tam angiüiLBD, LDB, ex conftrudione, quam LIH, LHI, propterparallelasD B, Hl, tequales fuut'»; eruntquo-«incafu que ^ tam linese LD, L B, quam L H, LI j ac proinde amp; com-fig II 8c pofitae “ vel refidus * D H , BI aequales. Cum autem , an-fimili- gulis D BI, H B G iifdem, five tequalibus exiftentibus ,addito %nbsp;vel ablato communi angulo H B I , angulus DBH angulonbsp;IBG,ideft®, BGK, fiat atqualis, atqiie angulus B D H eXnbsp;conftrudioneanguloDBI,ideft^,BKG,fitsqualis: erunt ®nbsp;triangulaBD H, G KBaequiangula, eritque proinde », utBDnbsp;ad D H live BI, hoe eft , ad G K, ita eadera G K ad K B.nbsp;cincafu quare,utfupra quot;, quadratumapplicatx GK redangiilo DBKnbsp;% 11.8c jequale erit. Quod eft propofitum.

(fincafib. fig. IIIScIV, autfimilibus. ^ per ilt;)primi. ^ per primi. ^ per primL 9 per 4fexti. «o ptr 3 4 primi. gt;' per 17 fexti.

Conftat itaque, curvam interfeftione, uti praedidum eft, defcriptam, eamipfam eftè, quseVeteribus Parabola ; Tolumque idem pumftum quod vertex; lineam autem defcrïbentem infiatione prima eandem quae diameter, aut ft angulimobilesr quasaxis; inter'nbsp;'valium verb idem quod latus rebtum five recentioribusnbsp;Parameter ad eandem diametrum eundemvè axem per-tinens; atque efficienti parallelas, eas, quas ordinatimnbsp;ad diametrum vel axem applicatae dicebantur; quare dcnbsp;eadem nomina retinento.

Corollarium I.

Cum defcribentis ejpcieMisipue interfedio quibufcunqiie ftationi-bus in uno tantumpundo fiat,raanifeftum ^^^defcribentem in qua-

cunqus

-ocr page 193-

Lib. I. Cap.

I. nbsp;nbsp;nbsp;lé’y

D nbsp;nbsp;nbsp;B

1

i

/

T (

/ ^ M

Ö

X

oh—^^

cunque ftatione, id eft , reiftas omnesnbsp;diametro tequidiftan-tes , in uno tantumnbsp;pun6to Parabola oc-currerc.

Corollarium x.

Cumque continuo defcrtbentis a Polo re-ceflu major major-que femper fiat an-gulus, quern crus effi-ciens conftituit ad li-neam ejjicientem in-ftatione frima ^ velutinbsp;G BI, manifeftumnbsp;eft , quamlibet re-lt;ftam iiPolo ad quodlibet curvte punéiumnbsp;dudam, ut, ex. gr.,nbsp;B G , totam intra Pa-rabolam, produélamnbsp;autem, utiadR, extra Parabolam ca-dere.

Corollarium 3,

Conftat prsEterea angulum G B K indefinite quidem di-minui, omnique pro-pofito angulo relt;5i;i-lineo minorem reddinbsp;pofte; fed crus tarnennbsp;B G nunquam cumdeyrri^f»^eBKcoincidere, multb mi-ipfarn tranfire: ad hoc cnim neceflum foret, ut crm patiens

X 3 nbsp;nbsp;nbsp;BH

-ocr page 194-

ï66 Elem, Cvrvarvm

' BH direürici EF toret parallelum aut certèut caderet infra fWW'-nbsp;nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;^ pg/g JureBvici squidiftans duéta eflet, quod plane im'

poffibile eft, cuni direUdcem femper fecèc.

Corollarium 4.

^juxia

Cor.pr^e-

Ideoque apparet, reclas omncs, quae Parabol* axemveldia-mccrutn fecanc, productas tandem Parabol* occurrerc. Secet cnim rcdta K X diametrum B K M , ac crus efficiens B G, in eafta-tione conftitutum , ut KBG angulus minor fit dato angiilonbsp;MKX perParabolam tranfeatin pundoG. Qj-ioniamigiturnbsp;reda KX cruri BG occurrit, auteidcmoccurretinter BScG,nbsp;’^Ifer 'co-nbsp;nbsp;nbsp;nbsp;produdaetiam curv* B G occurfuraeft gt;,auteidctn

rol.zhu- in ipfo G pundo occurret, quocafu amp; fimul Parabol* ibidem jus. occurret, autdeniquc ipfi BG occurret adpartes Gprodud*,nbsp;¦4perCor. quo utiqiic cafu prius Parabol* occurretnbsp;I hujus.

Corollarium 5*.

Manifeftum quoquecft, applicatasonines,utrinque Parabola terminatas, abaxe aut diametro bifariam dividi. Vt, fidudafitnbsp;5 per I applicata N M O, quoniam ^ tam quadratum N M quam qua-hiejus. dratumMO *qualeeftredangoloDBM: eriintquoqueeademnbsp;quadrata inter fe *qualia, ac proinde amp; red* N M, M O *quales.

Corollarium 6.

Patet quoque pr*cedentis converfum, nempe non pofle alias redas pr*ter eas, qu* ejficienti *quidiftant, in Parabola ab axe five diametro bifariam 1'ecari. Si cnim O Q^, qu*non fit*quidi-ftans ipfi A C, ab axe five diametro B P bifariam divideretur in P,nbsp;duda O N efficienti A C parallela , qu*que proinde ab eodemnbsp;« per Co- axe five diametïo bifariam quoque fecabitur in , foret O P adnbsp;rot. pree- P Q_, ut O M ad MN: ideoque ’’ duda reda per N amp; Q. efletnbsp;diametro parallela, ac Parabol* occurreret in duobus pundis Hnbsp;Jéxti. amp; Q; quod fieri non poteft

coroLi Itaque non folüm applicatae omnes a diametro bifa-hiijM. riam dividuntur , fed amp; qux a diametro bifecantur ad

eau-

-ocr page 195-

L I B. I. C A p. I. nbsp;nbsp;nbsp;i(?7

tandem ordinatim applicats funt: amp; fi diameter re-ftam quamlibet in Parabola ductam bifariam dividat omnes quoque ipfi xquidiftantes bifariam fecabit.

Corollarium 7.

Ex detnonftratis quoque facitè colli-gitur, applicatarumnbsp;quadrata ad fe invi-cemefle, ficut ad ienbsp;invicem funt diamc-tri portiones internbsp;verticctn amp; applica-tas intercepts. Vt,(inbsp;applicats (int G K,

N M , errt ¦ qua- ' i dratum redè; Gnbsp;ad quadratum ipfmsnbsp;N M , ut recSangu-lum D B K ad re-dangulum D B M,nbsp;id eft S ut B K ad inbsp;BM.

Corollarium 8.

Ex ipla porró de-fcriptione manife-ftum eft, effcientem in fiatione fritnti, id eft,nbsp;reélam, qusper Po-lum five verticem ap-plicatis squidiftansnbsp;ducitur, ibidem Pa-rabolam nee in a-lio prsterea punftonbsp;contingere , multónbsp;minus eandem feca-re.

-ocr page 196-

lé'S 'Elem. Cvrvarvm

re. Sumpto enim in curva praeter Polum B punfto utcunque, vela-ti G, fi crus ejjiciens eidem applicetur, uti in pofitione B G, confti-tuetur ab iplo amp; ejficiente angulus,ut G B C; atque adeó pumftam G, utcunque fumptum, id eft, tota Parabola, prteter Polum B , infra ejjicientem ABC cadet.

Corollarhm 9.

Conftat quoqueex antedidis, nonpoflè aliamredamprseter ejficientem Parabolam in PoIo(qü. vertice contingere. Quoniamnbsp;enim aliaquasvis redaper Bduda, ex.gr., PR, anguliuncon-ftituit cum efficiënte A C, ut R B C,(I a Polo ad dtreBricem ducaturnbsp;reda BH, ita ut eidem angulo R B C Eequalis fit angiiUis D B H,nbsp;acper pundumHagaturredadiametro parallela, ut HG: eritnbsp;ea ipfa defcribens, amp; H B R angulus mohilis, utpote sequalis angulonbsp;mobili D B C; BR verb crusefficiens'. acproinde ipiarum HG,nbsp;B R interfedio G in Parabola. Quare cum reda P R non innbsp;pundo B folummodo, fed amp; in pundo G Parabol^ occurrat, acnbsp;3 ffrCfl- tota BG reda ^ intra ciirvam cadat, non continget reda PRnbsp;rol.ihu- Parabolam, fedeandemfecabit.

jus.

Itaque omnes reds in Parabola duftiE, quaecontin-genti in vertice teqiüdiftant , ordinatim ad diametrum applicantur five ab eadem diametro bifariam dividun-tur; amp; contra, quas cuilibet reélae, a diametro bifariamnbsp;. divife, per verticem jequidiftans ducitur, Parabolamnbsp;in vertice contingit.

Corollarium 10.

Ex didisquoque obviiim eft, quopado data pofitione Parabola’ diametro, ejusque vertice, amp; latere redo , nee non angulo, quem ordinatim applicats faciunt ad eandem diametrum, ipf*'nbsp;Parabola in plano defcribatur.Si enim defcribendte Parabola diameter fit B K , vertex B , latus redum ad eandem diametrumnbsp;pertinensBD, (quodquidemipfidiametro in diredumfitpofi-tum,) atque angulus quem faciunt ad didam diametrum ordinatim applicata ABKvelCBK: oportet, duda per D. lateris redi

termi-

-ocr page 197-

lé’p

terminum reda E D F in angulo E D B ipfi A B D X(^^\\,eff.cien-tehC,8c intervallo BD,zd MreEincem E F curvam defcnbere, uc N BG: eritquehscipfa, qux defcribendapropomturParabola.nbsp;‘FmlLnbsp;nbsp;nbsp;nbsp;Ynbsp;nbsp;nbsp;nbsp;Theo,

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gt; oe 1 iiijus.

* per I

hujus, er

17/èxtj,

t jQ E L E M. C V R V A R V M

Theorema II.

^rd^ofitio z.

Si per aflumptum utcunque in Parabola pun(n:um regt; lt;fta ducatur, axi diametrovè parallela, erit quoque af-fumpcum punftumParabol«vertex, duftaqueparalleianbsp;itidem diameter,

SitParabolaquïelibetH AM, cujusaxis diametervè AB, 8c latus redutn ad eandem pertinens A C; fitque per putKStum M,nbsp;in curva utcunque afl'umptum , duöa reda MO, axi five diametro AB parallela: dico afl'umptum quoque pundum M verti-cem, didamqueM O'diametrumefl'e; imófiduda, perMredlnbsp;S V , ica ut ab axe five diametro A B extra Parabolam abfcindaCnbsp;portionem AI aqualem A B, qux inter vertieem A amp; applica-tam MB intercipitur,- produftaque O M ad K, ita ut fit MKnbsp;ipfis A B vel AI amp; I Mi tertia proportionalis, efficiënte S V, inter-^nbsp;valle veró M K Parabola defcribatur : dico haiic cum expofitanbsp;ParabolaH A Meandemfore, ita ut altera alteri per omnia con-gruat, ac proinde non folüm MO diametrum, atque M vertieem fore, led amp; M K latus retSlum eflè ad diéiam diametrum M Onbsp;pertinens, amp; S V Parabolam in verticeMcontingpre, omnesquenbsp;ipfi parallelas in Parabola dudlas ab M O bifariam di vidi, atquenbsp;ad hanc ipfam M O ordinatim applicari.

Sit enim in expofita Parabola H A M affumptum prsterea aliudquodpiam punftum,ex.gr., H j fitque ab eodem duéèaH Gnbsp;ad axem five diametrum-A B ordinatim applicata , nee non H Onbsp;ipfi*S V atquidiftans, quarum prior, fi opus fuerit produtSa, redi*nbsp;KO occurratin E; pofteriorvero, itidemproduda , ubiopüsnbsp;fuerit, prsdidlum axem five diametrum AB fecctinD. Etap^nbsp;paret fiquadratumreéiae HO a’qualefic reéiangulo KMO,nbsp;Parabolam, c^vtxefficiënteSV , intervalle veróM K defcribetur,nbsp;perpunftum quoque H tranfituram. ElTeautem quadratumre-ftï H O aequale reétangulo KMO multifariam id quidem, Sr»nbsp;meofaltem judicio, breviter fimpliciterque fatisin eumqui fe'nbsp;quitur modum demonftratur.

Quoniameft * ut C AadMB, ita MB ad BA,erit, dupljquot;

catis

-ocr page 199- -ocr page 200-

Elem. Cvrvarvm

catis confequentibus, ut C A ad duplain MB feu ad GE bis, ita

priZ,amp; M B ad BI, hoe eft S ita H G ad G D; ac proinde contentum

fiib mediis,nempe redtangulum H G E bis, sequale contento fub

extremis, nimirumredangulo fub GAamp;GD. Viidecumbi'

na quadrata reftarum HG amp; BM feu GE aequaliafint ^ binis

reótangulis C A G amp; C A B feu C AI, id cft ^, redtangulo fub

CAamp;IG: erunt quoque, additis ^ demptifve * utrinque jequa-

libus, nimirumreöanguloHGE bis abuna, ac redtan^ulo fub a in cafunbsp;nbsp;nbsp;nbsp;°

fig.ISc CAamp;GDab,alreraparte compohta “ veirelidua , nempe fimili- quadratum EH ac rediangulumfub CAamp;IDfeuMO aequa-

bus. li, £

^incafu nbsp;nbsp;nbsp;, ,

fig. 11 amp; 111 ac fimilibus. 7 quippeperJïtpra demonjiratareEfangnlum H G E bis acpuah eflre-Bavgulofub C\é‘G'D. £ in cafu enim fig. I, fi ab una pai tead bina quadrata reffarum HG amp; GE addatiirreüangulumHGEbis, compofitumfit EHquadratum, per 4fe-cundi; acfiab altera parte ad rcdlangulum fub CA amp; IG addatur redtangulum fub C Anbsp;amp; G D, fit, per I fecundi, re£l:ingulum fub C A amp; ID feu M O. Eodem modo, fi in cafi-busfig. II amp;IIIabunaparteabinisquadratisreaarumHG amp; GEauferatur reftangu-lum H G E bis, refiduum erit, per 7 fecundi.E H quadratum; ac fi ab altera parte a reftan-gulofubC Aamp;IG auferaturreftangulum fub C A 8c GD refiduum erit, per i fecundi,nbsp;redtangulum fub C A amp; I D feu M O.

Ideoquecum fit ut BM quadratum ad MI quadratum, five ut

8 nbsp;nbsp;nbsp;per r C A B reéiaiigulum ® ad redtangulum fub K M amp; A B 9, hoe eftnbsp;hujus, amp; ut CA ad KM, feu, aflumptacommuniakitudineM O, utpras'

didum redfangulumfub CA amp; MO ad KMO redangulum»

9 nbsp;nbsp;nbsp;perip ita quot; EH quadratum ad H O quadratum j fitque redanguluna

/êxtiyCr nbsp;nbsp;nbsp;CA amp;MO, ut jam oftenfum eft, sequale quadrato E H-

ex Jypo- nbsp;nbsp;nbsp;q^Qq^g II redangulum KMO quadrato H O sequale.

lopêr I Vnde cum pundum H , ubicunque id in expofita Parabol* fexü. A H affumptum fuerit, femper quoque fit in Parabola, quse effi'nbsp;‘‘ per 4 cietite S V, tntervallo verb M Kdefcribitur: fequitur alteram altequot;

171

4 fixti.

4 per 16 Jèxii.nbsp;f per Inbsp;hujus.

6 per I

Ihi

riper omnia congruere, ideoquehanc cumilla eandem.eflej k*quot; ie per 14 Ut conftet vcritas eorum, quse proponebantur.

^ nbsp;nbsp;nbsp;Coramp;llarium i.

, nbsp;nbsp;nbsp;Exantedidismanifeftum eft, quód , dudis in Parabolabioi*

quibuflibet redisfibi invicem sequidiftantibus, quse utramqt*^ bitariam dividit reda linea illius diameter exiftat, Quippe qu^nbsp;per medium sequidiftantiumunius diameter ducetur, fivehsc fitnbsp;ipfa diameter ex generatione, fiveeidem parallela, permediiui*

quoquot;

-ocr page 201-

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-ocr page 202-

174 Elem. Cvrvarvm

far con. quoque alterius sequidiftantium tranfibit *. Atque ita apparet, ckfionem quo pado datse cujuflibet Parabolse diametrum fimulqueordiiu-hups' ^nbsp;nbsp;nbsp;nbsp;eandetnapplicatas invenireliceat.

CoroUarium

» in 1 hu-jus. i per 9nbsp;Cor. Inbsp;hu jus.

Patetqitc porrb, quaflibet redas Parabolam ubivis contingent tcs, atqueoi'dinatim apundo eontadusad diametrumapplicatas, sequaks utrinque a vertice diametri portiones abfcindere;nbsp;amp;, vice versa a terminis applicatarum per diametrum dudas, ita'nbsp;ut asquales utrinque a vertice diametriportiones duöas applica-ta:que abfcindant, Parabolam in didis terminis contingere. Re-öam enim S V, ex eo quöd squales fint AI, A B, Parabolam innbsp;pundo M utcunque aflumpto contingere, nunc * demonftra-tum j at nee aliam redam in pundo M Parabolam contingerenbsp;poile, fuperius ^ oftenfum eft.

CoroUarium 5.

6 ^

hujus, ejufjuenbsp;Cor. 1.

per 1

itcrum redamper Iamp;M. quippeconftat-exantedidis ipfain IM omai cafu Parabolam co*tingcre in pundo M.

Co-quot;

Atque hinc non difficulter colligicur, quo pado a quolibet pundo, non intraParabolam dato, redaducatur, quasParabo-4 per I contingat. Inventis enim diametro quacunque amp; redis,nbsp;CoroJ. 1 quse adillam ordinatim appljcantur, fiin ejufdem diametriter-mino fit datum pundum, notum nunc eft ^ redam per idem pun-cir^Co- dum dudam, atque ordinatim applicatisjequidiftantem. Parare/. I hu- bolam ibidem contingere. At fi alibi in ciirva fit pundum datum,nbsp;j“s. velutiM, fitqtieinventadiameter AD: oportet, dudaexMre-daMBipfi AD applicata, fumptaque AI ipfi A.Basquali, duce-re redam per I amp; M. Sin autem extra curvamdetur in diametronbsp;produda, vclutil: oportet, fada A B ipfi AI jequali, atque B Mnbsp;ordinatim ad A D applicata, quse Parabols occurrat in M, ducerenbsp;rurfus redamper Iamp;M. Atvcrbfineque incurvanequeindia-metro produda detur, ut, fi inventa diameter fit M O, datumqiicnbsp;pundum I; oportet, dudal D diametroM O parallela, quatParabolam fecet in A., fumptaque A B ipfi AI sequali, atque ex Bnbsp;duda B M ordinatim ad AD applicata, nimirum, quataequidi-ftans fit contingent! in A, Parabolteque occurrat in M, ducere

-ocr page 203-

ijS



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«

ïyé

1 m 1

hums.

ï per I hujus.

'i per 17 fexti.

4 nbsp;nbsp;nbsp;pernbsp;pritni.

5 nbsp;nbsp;nbsp;/Jer 4nbsp;fexti.

^ in z hujus.

ftratafunt. Parabol»diametris AB, MO, aeparametris

E L E M. C V R V A R V M

CoroUarium 4.

Conftat prxterea, aflumptae cujuflibet diametri parametrutn efl'e tertiam proportionakm duabus redis, quarum unaeftvelnbsp;axis vel date diametri portio, interceptainter ejuf^em vertieemnbsp;amp; cam, quje Parabolam in affumpte diametri termino contingit,nbsp;altera verb ea prsedidse contingentis pars, quae inter datam amp;nbsp;aiFumptam diametrum interjacet. Demonftratum enim eft ‘nbsp;nbsp;nbsp;nbsp;.

redam MK, exeoquódipfis AI, IM tertiafitproportionalis, afliimpte utcunque diametri M O parametrum elTc.

CoroUarium 5'.

Ex demonftratis quoque non difficulter colligltur, quo padoj data pofuione qualibetParabolx diametro, ejusquc vcrtice, Scnbsp;latere redo , nee non angulo, quem faciunt ordinatim ad didamnbsp;diametrum applicate, aliaejufdem Parabolse diameter, quacumnbsp;applicate alium quemlibet angulum conftituant, acipfius vertex, amp; latiisreduminveniantur. Si enim data pofitione diametro M O, verticc M, amp; latere redo M K , anguloque S M K velnbsp;VMK, quem applicatae faciunt ad didam diametrum MO,nbsp;aliam cjufdem Parabol» diametrum invenire oporteat, quacumnbsp;applicat» angulum conftituant asqualem dato cuilibet angulonbsp;A B M: ducatur a termino K ad S V reda K P in angulo K P Vnbsp;ipfi dato A BMsequali, divisaque P M bifariam in I ducatur pernbsp;I reda I B ipfi M O squidiftans. Deinde ab M ad eandem I Bnbsp;applicetur reda M B in angulo M BI dato angulo »quali', divisa-c]ue BI bifariam in A, erit qusfita diameter A B, vertex pundumnbsp;A, ejusque parameter A C, reda nempe, qu» iplis A B, B M ter-*nbsp;tia proportionalis exiftit. Eft enim ^ pundum M in Parabola,nbsp;qite efficiënte ipfi B M parallela ac intervdlo AC defcribitur,quan-doquidem quadratum applicate BM ex conftrudione ^redan^nbsp;gulo C AB cftsequale. Deinde quoniam fimilia funt trianguknbsp;B IM amp; PM K,ob squalesangulos adB amp;P(ex conftrudione),nbsp;atquead I amp; M'* (ob parallelas A D , M O ) erit 5 ut BI ad iNÏ»nbsp;itaPMadMK. amp;, fumptis antecedentium dimidiis, utAI^dnbsp;I M, ita IM ad M K. Qiiare fecundum ea qu» fuperius ® demonquot;

-ocr page 205-

177



-ocr page 206-

178 Elem. CvrVarvm

MK, indiöisangulisdefcriptsEomninoexdemerunt. Suntau-tem amp; anguli, qiios faciunt M B alia^que ad diametrum A D ap-plicatïej ex conftrudione, dato angulo A B M squales. Quocirca cft'edlutn eft , quod qusrebatur. Quód fi verö datus angulusnbsp;A B M redl:us fuerit, ipfe axis erit, inventa A D.

Etiamfi curva, quilibet efficiënte, amp; quocunque in-?Ê’rx’lt;2//ödefcripta,{i anguli mobiles iiiaequales fmc iis, qui lèAdireSlricem^ViXsx. abeademparte, eaipfa fit, cuipoftnbsp;Circulum amp; Parabolam inter curvas primi generis pri-mum locum tribuam , utpote quam fequenti fpecienbsp;quodammodo fimpliciorem judicem ; cujusque pro-pterea ortum , naturam , amp; proprietates nunc expo-fiturus eidem defcribendi methodo infiflere, praemiflif-que in principio definitionibus inhxrere pofïèm; cumnbsp;tarnen ea ipfius proprietas , quamprimam ac maximènbsp;univerfalem exiftimo , amp; è qua csteras facillimè deduce , ex aliis generationum fpeciebus diftinftiüs ap-pareat atque expeditiüs demonftretur , quod in Ma-thematicis, amp; priecipuè in Elementorum explicationenbsp;non parvi faciendum puto, earn felegi, qux a jam di-(R:a quam minimum, defleftat, quaeque fimiliter angulinbsp;re(3:ilinei reéteque lineae motu amp; interfeélione perfi-citur ; at in qua difti anguli motus non circularis fednbsp;redus, ac contra diftx lineae non redtus fed circularisnbsp;eft, ut ex definitionibus in eum finem adaptatis j amp; fe-quenti Capite propofitis, rnagis elucefcet.

C A P V T II.

DEFINITIONES SECVND.^.

CI refta linea circa punftum fixum circulariter mo-ta angulum quendam reftilincum , altero fui crure

immo-

-ocr page 207-

Lib. I. Cap. II. nbsp;nbsp;nbsp;179

immotae revise lineas applicatum , per eandem immo-tam lineam promoveat, amp; fecum ducat, ita ut prsidi-fta recta circulariter mota femper per idem applicati cruris putuflum tranfeat, fimulque alterius cruris acnbsp;ejufdem lineae motse interfedtione curva defcribatur,nbsp;appellabitur haec ipfa circulariter mota linea defcribens.

II.

Altera verb immota manens Tgt;ireBrici5 nomen reti-nebit,

III.

Praediiftus autcm angulus redilineus, isquequieiefl; deinceps, fimiliter Scliic Ajigulorummobilium nominenbsp;venient.

IV.

Sicuti ’amp; pundum fixum, circa quod defcribens circulariter movetur, Tolus nuncupabitur.

Rurfusque crus anguli mobilis, quod a deferibente per direSirkem promovetur, Crus pattens.

VI.

Alterum autem crus , quod a deferibente iecatur, ^^useffictens, amp; per anguli verticem produftum Lineanbsp;^Sciens appellabitur.

VII.

Cum defcribens efficienti parallela eft ac proinde nulla ^^arum interfeftio exiftit, tarn efficientem quam deferi-^ffitem in fiationeprima conftitutas dicemus; ac queries de ii$ fimpHciter fermo erit, in *ali ipfas ftatione con-

«aerabiiW

Z a nbsp;nbsp;nbsp;VIII.

-ocr page 208-

l8o E L E M. C V R V

VIII.

Intervallum autem liic nominabimus tam eam Cruris patientis partem, quseinter angulimobilis verticemamp;nbsp;defcribentem interja'cet, quam eam defcribentis portio-nem, quse inter ‘Polum amp; direSiriccm intercipitur.

Vt in appofita figura, firec5i:a ABC' circa A punftum cir-culariter moveri concipiatur, motuque fuo promovere amp; fecum quK ducereangulumBE C'j ita ut crus E B femper applicatum ma-quidetn immotïE rcftse linear KL, ac praedida ABC mobilislem-

ABC nbsp;nbsp;nbsp;fitnul-

8c angu- que alterius cruris E C amp; didae linear A B C incerfedione C de-lus B E C ('cribatur curva linea c C, fitque duda A D cruri E C parallela: infigura apparef^ quomagis reda AB Cadipfam AD accedit, eómino-diftinAis fieri angulum E C B. ac tandem cum ipfa ABC pervenit adnbsp;ftationi- A D, itaut cum ipfa coincidat ,eundem angulum E CBtuncpe-bus exhi- nicus cvanefcerc: cum A D,ac proindc amp; dida A B C,ftatione il-bentur. ja ^nbsp;nbsp;nbsp;nbsp;^ parallela fit j ita ut tune didum crus E C five reda

CEM eadem fit cum linea GFH, nimirum fuppofita DFipfi B E, tequali, eruntquenbsp;ABC defcribens in ftationibus diverfis.

KL direBrix.

BEC, BEM, fiveDVGangnlimobiles.

A BPoIhs.

EB cmspatiens.

E C cms efficiens.

M C linea efficiens.

GFH effictensin Jlatione prima, feu ejficiens fimpliciter.

A D I defcribens infiationeprima y fexs defcribens E B feu F D amp; A D üXtwxaapiamp;intervallHm.

Theorema III.

Propojltio 3.

Quibuflibet angulis mobilibus ac quibufeunque i^' tervallis , juxta definidones praemiilas defcripti cur-, hoe ipfi proprium erit , ut reftangulum conteti-

tuiï»

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L I B. I. C A p. II. nbsp;nbsp;nbsp;i8i

turn fub qualibet refta efficientï parallela, a quocunque curvx punfto ad direBricem duéla, atque ea direEiricisnbsp;parte, quae inter did:am parallelam amp; efficientem inter-cipitur, aequalc fit ei, quod fub utroque ïntervallo con-tinetur, redangulo.

Ai

V

Sit quolibet anrulo mohili B E C, amp; quibufcunque intervallis E B, feu F D amp; A D, direBrice K D L, defcripta cu rva r C; ita u tnbsp;ffficiens fit G F H, fitque a pundo C in curva utcunque affumptonbsp;ad dtreBricem dudla C E efficienti G F H, ac proinde amp; intervallonbsp;A.D parallela: dico reftangulnm FE C aequaleeffe ADF re-öangulo, five ei, quod fub A P, E B continerar.

Z 5 ~ nbsp;nbsp;nbsp;Con-

-ocr page 210-

l8^ Elem. Cvrvarvm

' per primi.

per 4 fixti.nbsp;i per 16nbsp;fexti.

Conftitutis enitn tam mgnlo mobtli quam deferibente in ftationc utifuêre, cum per ipfarum interfeftioncm deferiptum eft pun-(ftiim C, veluti in B E C, amp; A B C, quoniam a:quales funt recftjenbsp;EB, FD, additavcl ablatautrinque FB vel ED: eruntquo-queredsE BD, FE aEqualesj cutnque ' propter parallelas EC,nbsp;A D jequiangula fint triangula B D A, B E C; erit ^ ut B D, idnbsp;eft, F E,adD A,itaBE adÉ C: ideoque ^ redangulum FE Cnbsp;fiib extremis xquale rcdangulo fub mediis A D, E B feu A D F.nbsp;Quod erat propofitum.

4 inEpt-jiola ad Schote-

Quare cum amp; omnia reflangiila, ut FE C, inter fe quoque fint^qualia , manifeftumcft, curvam, interfe-ftione , uti prsdidum eft, deferiptam, earn ipfam eftè,nbsp;quam Veteres Hyperbolam vocarunt, aut, fi binas cur-vas eodem amp; continuato motu genitas finiul confide-res, efte eas, quas Oppofitas Se6tiones.dixere: dire^ri-cem verb K L ac efficientem G H eas ipfas, quas Afym-ptotos nuncupqyerunt, atque ipfarum occurfum fivenbsp;interfeeftionem, ut F, idem illud puinftum, quod Hyperbolas five Oppofitarum Seeftionum Centrum ab ipfisnbsp;appellatum fuit. ideoque amp; base fingula iifdem illis nominibus in pofterum indigitabimus , folummodo fe-(ftionum nomen, ob rationes fuperiusexpofitas, minusnbsp;congruum evitaturi. Re(ftangulum autemfub intervallisnbsp;contentum, feu, quadratum ei aequale, Hyperbola Po-tenciam dicemus.

Corollarium i-

^ per 16 Jexti.

Ex ipfa deferiptione manifeftum eft,Afymptotos amp; Hyperbo-lammagis magisque adfe invic«m continue accedere, tandem-que pervenire ad diftantiam, dataqualibet diftantia minorem 1 cujus tarnen , fi demonftrationem exadiorem defideres, data diftantia fit leda N O , ad Afymptoton F K perpendicularis. Sum-pta igitur N P, quae eadem N O minor fit, fi fiat ut N P ad A D,nbsp;itaDFadFe, aepert ducaturecipfi NP aequalis atque Afym'nbsp;ptoto FH xquidiftans: erit^redartgulumFecPotetitiae AD F

jequa-

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Lib. I. Cap. II.

quale, ideoque juxtaca, quas * demonftratafunt, punSum C in 6 nbsp;nbsp;nbsp;3 hu.

Hyperbola. Eft autem amp; c f ipft P N squalis, hoc eft, data di-i*^**

nt

it/

At

ftantiaN O minor.Quareamp; perpendicularisa punifto cad Afym-ptotonFKdufta, id eft, diftantia Hyperbolae a praedida A fym-P^oto, ibidem data diftantia N O multo minor erit.

Coroll arturn

Atque ita Gmul apparet, reftas omnes, qu3e duSaE ex quolibet pvmao intra angulum, quiad verticemeftei, qui Hyperbolamnbsp;'ontinet, per centrum tranfeunt, vel Afymptotorum alterutramnbsp;fecant, Hyperbolae tandem occurrere , produdtasque eandem, amp;

in.

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184 Elem. Cvrvarvm

inuno tantum puiiélo, fecare: quandpquidem has produdseab ucraque Afympcoto magis magisque femper abfcedun t.

Corollarium 5,

Conftatprseterca, effieientem inquacunqueftatione, ideft , re-6ias omnes Afymptoto parallelas limiJiter Hyperbolae, amp; qui-dem in uno tantum punlt;5to,occurrere,prodult;5tafque illam ibidem fecare. Impoffibile enim eft, ut defcnhens atque efficiens ulla ftatio-*nbsp;nefefeinpluribuspundisinterfccent. .

Theorema IV.

Tropfitio 4.

Reéla linea, five pet bina quselibet in Hyperbola puti-lt;5ta tranfiens, five eidem ita occurrens, ut produt^la u-trinque extra Hyperbolani cadat, utrique Aiymptoto, intra angulum, qui curvam continet, occurrit.

Sint in Hyperbola BCD, cujus Afymptoti KA E, HAF,

dudae F B C G, y tranfiens per bina

\ nbsp;nbsp;nbsp;/• /,. curvsE punda B

C, atque M C ei' / /nbsp;nbsp;nbsp;nbsp;dem occurrens in

I-VOv nbsp;nbsp;nbsp;/ /nbsp;nbsp;nbsp;nbsp;C, itautproduda

versus L utrinque extra Hyperbolatnnbsp;cadat j Dico tamnbsp;redara F B C Gnbsp;quam redamMCLnbsp;utrique Afymp totonbsp;KAEamp;HAFin-tra angulum E AFnbsp;occurrere. Hoce-nim fi. non accide'nbsp;ref,eadem F B C Gnbsp;vel M C L autnbsp;Aiyni'

-ocr page 213-

1 I B. I. C A B. IL nbsp;nbsp;nbsp;l8y

Afymptotorum alterutri parallela cHet, aut, fi tel hulc vel illi Afymptoto extra angulum E AF occurreret, ex puncto iiitra an-gulum K A H ad verticem ei qui Hyperbolatn continet duClanbsp;hanc vel illam Afymptoton fecaretj ideoque' curvjeinunotan- i per znbsp;rèm pundto non verb in duobus occurreret, ac produda eandem amp; 3 Cor.nbsp;iecaret, non autem utrinque extra Hyperbolam caderet, contra ^nbsp;id quod ponitur. Acproindcconftatpropofitum.

Theorema V.

Tropojitio y.quot;

AlTumptis , vél in una eademque , vel in oppofitis Hyperbolis, duobus utcunque pun(5lis, dutftisque pernbsp;eadem five una reét^ five duabus, fibi mutuo parallelis:nbsp;erunt reélangula fub duélx vel duélarum partibus, Hyperbola amp; Afymptoto utrinque interceptis , fibi invi-ccm aequalia.

r.

Hy

Sintj vel in eadem, vel in oppofitis Hyperbolisnbsp;B P C D, cujus Afym-ptoti A E, A F, afliim-pta utcunque bina pun-da B amp; C , ac per ea-dem dud£E bin£e redsenbsp;B D , C P fibi inviccm« qy.;

_________ parallelse Afymptotif-tique oc-

,SïX nbsp;nbsp;nbsp;/:nbsp;nbsp;nbsp;nbsp;que occurrentes in pun-

öisE.F.G.H-dkoSf-fquot;: redangulum E B F re- rs fitin-dangulo G C H asquale traangu-eflè.nbsp;nbsp;nbsp;nbsp;^

•V Dudis enim per ea-huju^s!'*'

dem punda B amp; C tc-' periS dis, utrique Afymptotonbsp;parallelis alteraqucnbsp;nbsp;nbsp;nbsp;‘

rymptoto terminatis, BI, B L, C K, C M: erit *, propter redan- 3 per'zf gala IBL amp; K.CM*lt;equalia, utiBadKC, hoceft^j utEBf»'2’y»gt;ó*

A a nbsp;nbsp;nbsp;ad» .

-ocr page 214-

186 nbsp;nbsp;nbsp;E L E M. C U R V A R U M

* nbsp;nbsp;nbsp;fur t6 -sdXSrC, ita CM ad B L, id eft, iti C H ad B F. ac proinde re*nbsp;fexti. (ftangula E B F amp; G. C H aeqaalia funt. Quod demonftrandum

erat.

Eodem modo oftendetur, fi perbina punda, utBamp; D, una reéla ducatur B D, qiise utrique Afymptoto ocJ-

• nbsp;nbsp;nbsp;currat in punftis E amp; F'', feid:angula E B,F, F D E fibinbsp;invicem £Bqualiae/Ie,

Corollarium i.

In oppofitis Hyperbolis, ft parallelarum altera per centruna tranfeat, ut C P in tertia figura, e^em demonftratione compfo-batum erit, reétangula fub partibus quarumlibet refliarum, qujenbsp;per Afymptotosad utramque curvamducimtur, fingulasqua-lia efle quadrato aequidiftantis a centro ad Hyperbolam dueSae.nbsp;Quare cum cx dieftis appareat, fi, dudta per centrum reöaut*nbsp;cunque veluti C G P in eadem figura, eidetn ubivis alia refta re-quidiftans ducatur B D, quae fecet Afymptotos in E amp; F, redan-gulum EBF velFDEquadratoGCitemqueamp; GP quadratonbsp;aequale efle: fequitur, ipfasquoque GC, GP efle fibi invicenxnbsp;a:quales, hoc eft, quamlibet redam ad oppofitas Flyperbolas peenbsp;•centrum dudani, in eodem centro bifariam fecari.

Corollarium t.

Conftat qtioque cujuflibet redae, five per unam eandemquej five per oppofitas Hyperbolas dudse, partes Hyperbola amp; Afym-^nbsp;ptotis interceptas fibi invicem eflesequales.

^ fury hu]ns,amp;nbsp;fexti.nbsp;6 feY 17nbsp;qmnti.nbsp;t per 18

quiHti.

8 per 9 juinti.

Duda enim utcunqueBD, quse Afymptotisoccurrat inE amp; F, cum ex antedidis ^ BFfitadD F, utD EadBE: eritquoquenbsp;dividendo ^, vel, in oppofitis Hyperbolis, componendo ^, B Dnbsp;ad D F, ut eadem B D ad B E, ideoque D F , B E ®, ac proinde Sc.nbsp;B F, D E fibi inyieem squales erunt.

3-

Corollarium

Undepariterconftat, redam, quxvcluniuscjufdemque, vel oppofitarum Hyperbolarum, bina panda conjungit, nulloaliq

fui

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Lib. I. Ca p. II.

187

tFfjnt

tFt3.11.

gt;V

Ai

fuipundo in Hyperbola efle. Si enitn praeter D amp; B aliud quod-datn ipfius D B pundum, ex.gr. X, in Hyperbola foret, eflèt 'X¥' per Ce-^pfiBE acproindc amp; ipfi D F aequalis, parstoti, quod eft ab-

^urdum.

CoroUarium 4.

Facile atitem apparet, amp; converfum quoque propofitionis vc= rum effe: nempe, fi, iirdem pofitis, amp; redangulis E B F, G C Hnbsp;^'lualibus, pundorum B amp; C unum in Hyperbola fit, amp; alterumnbsp;5“oque foreineadem vel oppofita Hyperbola, cujus Afymptotinbsp;A E amp; A F, Ex eo enim quod sequalia fmt rcdangula E B Fnbsp;G C H, demonftrabitur squalia quoque elfe redangula AIBnbsp;AKCeadem methodoj quaconverJumfupraoftenfum fuit.

Jdeoque fi pundum B fit in Hyperbola, erit quoque * pundum z per 3 ^ in eadetn aut in oppofita Hyperbola,cujus Afymptotifunt A E,nbsp;nbsp;nbsp;nbsp;.

amp;viceversa. Debinisautempundis ineadcmlinea, utB - F), Hem didum efto; imo amp; idem erit in eadera linea, fi dida

•A a X nbsp;nbsp;nbsp;punda

-ocr page 216- -ocr page 217-

Cap. II.


185»


Mgt;


ri's

kv

squlangula funt triangula E 0 V amp; F O S : erit' ut E O ad gt; p^r 4 O V , ita F O ad O S. Quare cum E O ipfi F Ö fit xqualisnbsp;eritamp; * OV ipfi OS, hoc eft, rea^ OT xqualis, parstoti,»/-^^ 14nbsp;quod eft abfurdum. Non ergo bifariam fecatur reda R Q^a dia-metro AO.

Corollarium 7.

Atque hinc manifeftumfit, quod, fi velin unaeademque vcl adoppofitas Hyperbolas binas quselibet rease fibi invicem tequi-diftantes duasfint, qus utramqu.e bifariam dividit reaa linea

per centrum tranfeat leu diameter fit: Qiiippig qu^ per medium.

Unius sequidiftantium diameter ducetur , per medium quoque al-terius sequidiftantium tranfibit ^. Undeapparet, quopaa© datse 3 y ’ Hyperbolse vel oppofitarum Hyperbolarum diametros quotli-^quot;^quot;^' Snbsp;bet, fimulqucordinatim applicatasadeafdem, necnonamp;cen-trum, utpote quod binarum pluriumve diametrorura communisnbsp;interfeaio eft, reperire liceat.

Aa 3, nbsp;nbsp;nbsp;Theot*

-ocr page 218-

190

¦I fer a Cor. fnbsp;hujtis.

2 nbsp;nbsp;nbsp;^er 4nbsp;Cor. ƒnbsp;loUjus.

3 nbsp;nbsp;nbsp;per 3nbsp;¦Cor. jnbsp;hujuf.

^ per a Cor. fnbsp;hujus.

5 per J* htjus.

Elem. Curvarum

Tro^ojïtio 6.

Refta per quodlibet Hyperbolae punftum ad utram-qiie Afymptoron dufta, quaeineodem punfto bifariam dividitur, curvam ibidem contingit; amp; contra, contin-gens ad utramque Afymptoton produfta in punfto con-taftus bifariam divifa eft.

Sitper pundum C in Hyperbola B C DjCujus Afymptoti A E, AF, dudareda G CH, utrinque Afymptotisterminata , quscnbsp;ineodem punfto C bifariam dividatur. Dicoredam G H curvam contingere' in C. Secetenim, ii fieri poieft, refta GH Hy-perbolam in C. amp; I; eritque ‘ IH redseCG, ideoque amp; ipfinbsp;C H jequalis. quod eft abfurdiim. Non fecat ergo G H Hyper-bolam, fedeandemcontingit. Dicoporróconverfim, fiGHinnbsp;pundo C Hyperbolarn contingat, eandem quoque in C bifariamnbsp;dividi. Hoe enim fi non fit, furaatur in C H majori parte ipfa Hlnbsp;squalis G C. Hinc cum pundum C fit in Hyperbola, erit quoque * pundum I in Hyperbola, totaque Cl Hntra curvam cadet , ideoque ipfa G H Hyperbolarn non continget, fed eandemnbsp;inpundis C amp; I fecabit, contra id quodponebatur. Non ergonbsp;GC ipfi CH injequaliseft. Ideoquecafuutroque conftatpro-*nbsp;pofitura.

Corollarium ï.

Manifeftum itaque eft exantedidis, fingularedangula, quse comprehenduntur fub partibus cujuflibet redte contingent! pa-rallelse, inter Hyperbolarn amp; Afymptotosinterceptis, efl'eae-qualiadimidisetangentisquadrato. Ut,fitangentiGCH aequi-diftans utcunque duda fit B D, Afymptotis occurrens in E amp; F;nbsp;erit redangulum E B F five ‘‘BFD,utamp;FDE five DEB asqua-le redangulo G C H *, id eft, ipfius C H vel C G, dimidise tan-gentis quadrato.

-ocr page 219-

Lib. I. Cap. II

Corollarium z.


ipi


Patet porro, redatn, quje perdiametri terminum duciturae-^uidiftansei, quae in Hyperbola ab eadein diametro bifariam fe-

catur, id eft , ordinatim applicatis parallela , Hy-perbolam in diéto termi-no contingere. Ut, ft adnbsp;diametrum A N ordinatim applicata fit B N D,nbsp;quae produdta Afympto-tisoccurrat in E amp; F, acnbsp;per diametri terminumnbsp;C duda fit redta G C H ,nbsp;ipfi B N D squidiftans,nbsp;cum aequales fint N Fnbsp;Sc N E ‘ ; erunt * quo- gt; per znbsp;que C H amp; C G X-amp; S Ce-quales, ideoque ^ G C H ^^0 ^


VHT


Hyperbolam contingeti


qtunti, ' ^fexti.

3 per 6 ¦


Corollarium

Hinc liquet, nonfolumomnes redlas in Hyperbola, contin-S^nti parallelas, a diametro per tadtum ducfta bifariam fecari ^‘leoque ad earn ordinatim applicatas efle, fed amp; non pofte plu resnbsp;in uno eodemque punöo Hyperbolam contingere. Ut, finbsp;^ntingenti GH parallela fit BD, Afymptotisoccurrens in E \ujtts^nbsp;^ F j duöaper taétum C diametro A C N, qure duda;B D oc- i per pnbsp;^^trat in N: quoniam G C, C H aequales funt, nec non E N,nbsp;nbsp;nbsp;nbsp;01

F *, erunt quoque (demptis arqualibus '^EB,DF,)BN, ND^ ^qualcs, ideoque amp; ad didam diametrum A CN ordinatim ap-P‘cats. At verb non pofl'ealiam redam prater GH Hyperbo-inpundo C contingere,patet, quandoquidem amp; omnes ipfi ^nbsp;^^«diftantes in Hyperbola duds, quaeque alia: cftent quam pra-^ applicata, bifariam quoque per eandem diametrum divide-®*itur ^. quod fi.eri non pofte lupenus ® oftenfum eft.nbsp;nbsp;nbsp;nbsp;^


Cx-


Shwjits..


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I pi nbsp;nbsp;nbsp;E L ^ M, C U R V A R U M

Caeterum monendum hk , ut diametrorum quoqiie magnitude determinetur , earn], quae a quocunque in

« per Carol. i fhujuf.

JN\

Hyperbola punfto pec centrum du(fl;a oppennbsp;fiti Hyperbola termi-natur , ideoque inter-ceptae inter centrumnbsp;amp; curvam dupla eft%nbsp;ut C A P , vel Hyperbola , vel oppoS-tarum Hyperbolarumnbsp;tranfverfam ; diame-_ trum ; eamque , quaenbsp;in ipfius cermino curvam contingens utrin-que Afymptotis ter-^minatur, autquaeipfinbsp;per centrum aequalisnbsp;amp;parallela ducitur, ut G C H. f^cundam diametcumnbsp;tranfverfae conjugatam; at verb illam , quae ipfis P C,nbsp;G H, tranfverfae nempe fecund^que diametro tertia eftnbsp;proportionalis, ut C O, redum latus five Parametriumnbsp;dici.

Theorema VII.

‘Pro^ofitio 7.

Quae per terminum tranfverfae cujuflibet diametri refta ducitur, contingenti in vertice parallela, oppofi'nbsp;tarn Hyperbolam contingit, amp; quae ad fecundam dia-metrum , aflumptae cuicunque diametro conjugatam »nbsp;ordinatim applicatur, eidem affumptae diametro aeqm-diftat.

-ocr page 221-

*9?

Lib. I. Cap. II.

Sit Hyperbola, vel oppofitarum Hyperbolarum IC , HE, «juarum AfymptotiBG,DF, diametertranfverfa utcunqueaf-iumpta C E, pertjue ejus termiaum E duöa redta F E G paralle-

la ipfi B D, quje curvam in ver-tice C contingit, ita utbsecat-que ilia Afymptotis occurrant in punftis B, D amp; F, G: diconbsp;praedidam quoque F E G oppo-fitam Hypcrbolam concingercnbsp;inE; amp;li per centrum A duca-tur fecunda diameter A K, dia-inetro C E conjugata,ordinatimnbsp;ad eandem A K applicatas ipfinbsp;C E diametro seq uidiftarc. *nbsp;Qiioniam enim elt' tam A E 4r$xti.nbsp;ad E G, ut A C ad C B, quamnbsp;AEadE F, ut ACad CD; amp; cTol.lnbsp;funt tam A E, A C ^ quam C B, hupes.

C D ^ aequales , erit quoque ^ nbsp;nbsp;nbsp;^

^ tam E G ipfi C B, quam E F ipfi C D j ac proinde amp; E G ipfi lt;}uinH.

Ê F stqualis. Unde * reda F G * nbsp;nbsp;nbsp;^

oppofitam Hyperbola® H E continget in punfto E.Quod primo loco propofitum fuit. Porro fi per G amp; D ducatur refta G D, fe- gnbsp;nbsp;nbsp;nbsp;jj

cans fccundam diametrum AK inK, oppofitisque Hyperbolis ^ccurrens in H amp; I, cumsquales amp; parallel* fint E G, C D, ^ jnbsp;crunt amp; ^ qute ipfas conjunguntG D, C E parallel* amp; asquales.nbsp;Ideoque cum fecunda diameter A Kcontingentibus BD,F G, idnbsp;nbsp;nbsp;nbsp;^4

’ ordinatim ad diametrum C E applicatis*quidiftans fit, ut- primi. Pote ex Hypothefi ipfi C E conjugata : erunt quoque ® ted* ^ inbsp;GK, EA, ut amp;KD, AC, ideoqueamp;^GK, KD squales-^^J’nbsp;Quibus fi addantur squales '°GH, D I: erunt fimiliter red* 10nbsp;KI fibi invicem *quales. Quocirca cum quot; adfecundam Cor. ynbsp;diametrum AK applicata fit reda HI, etiam c*ter* omnesad ^nbsp;eandem applicat*' *eidemH I ac proinde amp; diametro C E *qui-diftabunt. Quod fecundo loco propofitum erat.nbsp;nbsp;nbsp;nbsp;hujtu.

tiperf amp; 6 Cor.

_, nbsp;nbsp;nbsp;s

Bb nbsp;nbsp;nbsp;Pro-

-ocr page 222-

» exhype -thefi. ,

^ pen j fexti.

3 per j hujus.

¦3 per f primi.

^ per ip primi.

^per ji primi.

7 peri6 primi.

* per fnp. demonjir.nbsp;^ per 6nbsp;igt;ujus.

1^4 Elem. Curvarum Problema I.

Tro^ofitio 8,

Datis quibufcunque diaraetris conjugatis, HyperboIlt;e axes conjugatos invenire.

Sint dat3E diametri conjugatae P C, G H, oporteatque invenirC conjugatos axes ejus Hyperbola , cujus caedem P C , G H conjUquot;nbsp;gatae diametri exiftunt.

Dudtis ab A centro per G amp; H Afymptotis A G, A H, dufta-que a C adeorum alterutramreda GB alterixquidiftante, fu-

matur inter A B, B C media proportionalisnbsp;AD. DeinduftaDEnbsp;ipfi A D aequali, atquenbsp;Afymptoto A H parallels , erit E A Fjnbsp;tranfiens per E amp; A acnbsp;ipfius E A duplajtranf-verfus axis qui quaeri-tur,atque IE K ad ean-dem perpendicularis,nbsp;ac utrinque Afympto-tis terminata, axis fequot;quot;nbsp;cundus, priori conju-gatus.

Quoniam enim punquot; ftumC ' in Hyperbola eft, reéiangulumque ADE ipfi A BCieqiiale®,- eritquoquonbsp;punótumE ^ in Hyperbola. Porrocumpropter recftasD A,D Enbsp;aequales aequalis quoque fit D A E angulus ipfi D E A, id eft Snbsp;E A K angulo, fintque amp; anguli A EI, A E K ex conftrudtiooenbsp;aequales: erunt ^ triangula A EI, A E K «equiangula, a tque ob Equot;nbsp;tus A E commune ’ etiam squalia, latusque IE lateri E K aequa-le. Unde cum punfium E* in Hyperbola exiftat, dividatquebiquot;nbsp;fariam reflam IK, utrinque Afyraptotisterminatam, conting^nbsp;ipfal K^curvaminE: ideoque, amp; propter angulosF E I, F E1^nbsp;reftos, conjugati axes erunt F E, IK.

Theo-

-ocr page 223-

Lib. I. Cap. IL Theorema VIII.

Tropojitio 9.

Quxlibet contingentes ab angulo Hyperbola Afym-ptotis comprehenfo jequalia abfcindunt triangula , amp; redlangula fub eorundem triangulorum lateribus coni-prehenfa invicem quoque asqualia funt, ac prsterea ma-jora eorundem latera a contingentibus, ipfaeque bafesnbsp;leu contingentes Afymptotis terniinats, inmutuooc-curfu, nec non ipfarum partes curvam contingentes inter occurfurnéc Alymptotos interjeftse, inpundliscon-tadus, in eadem ratione fecantur.

Hyperbolam CE, cujusAfymptotiAG, AK, redse GH,

IK utrinque Afymptotis terminatae, ac fibi mutuoinR occur-rentes, contingant in punftis C amp; E: dicotamretiangulaquEn triangula G A H, IA K sequalia cfle j ac p rseterea efle G I ad IA ,nbsp;ficutKHadHA; itemque GRadRH, ficut KRadRI j nccnbsp;non G C ad C R, ficut K E ad E R.

Dudis enim apundis contadus C amp; E redis C B,E D Afym-. ptotorum alterutri, ut A H, parallelis, cum fit utGCadGH, ita G B ad G A, amp; B C ad A H ' j fitque G H ipfiiis G C dupla *. ’nbsp;nbsp;nbsp;nbsp;4

Ï/

erit quoque tarn G A , iplms G B quam A H hujus,nbsp;ipfius B C dupla, ideo-que ^ redangulumG A 3 fenonbsp;H rcdanguli GB C ll-fixd-ve A B C quadruplum.

Eodetn modo redangu-lum I A K redanguli A D E quadruplum o-ftendetur. Hinc cumnbsp;sequalia fint redangula

B C, A D E , erunt quoque eorum quadrupla , nimirum 4 per j redangula G A H amp; IA K sequalia. Quod eft primum.

Unde cum ^ fit ut G A id A K, ita IA ad A H, triangula quo- ^^ ^

B b z nbsp;nbsp;nbsp;quc ’’

-ocr page 224-

6ptrtT

pxti.

7 per i6 ptinti.

^per If fumti.

9 per tf pxti.

gt;o^i»r i8 quinti.

per Co-nil. 19 quinti.

tg6 Elem. Cur varum queGAH, IAK squaliaemnt'®, utpotehabentia lateradrcanbsp;communem angulum, reciproca. Quod eft fecundum.

Ac cum permutando ^quoque fitG A ad I A,nbsp;utAK ad AH; eritamp;nbsp;® dividendo G I ad IA ,nbsp;•g /nbsp;nbsp;nbsp;nbsp;\ \jjnbsp;nbsp;nbsp;nbsp;ut KH ad HA. Quod

eft tertium.

Porro cum ab «qua-kJC libus triangulis GAH, lAK ablato communinbsp;quadrilatero I R HA,nbsp;refi3ua^ nempe triaa-gula G RI amp; KRH, quoquesqualiaremaneant, erunt® eorun-dem latera circa jequalem angulum ad R reciproca, id eft ,eritnbsp;GRadRHjUtKR adRI. Quod eft quartum.

Unde cum componendoquoque fitG Had RH, utKIad RI,aut,fump'tisantecedentiuradimidiis, C H adHR, utE Inbsp;ad IR: erit amp; per converfionem rationis quot; C H five G G adnbsp;C R, ut EI five K E ad E R. Quod eft quintum. A tque ita de-monftrata funt ea, quse proponebantur.

Theorema IX.

Tropojitio 10.

Dud:a quacunque in Hyperbola diametro, erit ut qua-dratum fecundse ad quadratum tranverfae diametri, five ut parameter ad tranfverfam diametrum , ita qua-dratum cujuflibet ordinatim applicatae ad. reftangu-lum fub ejufdem diametri partibus , utroqiie tranf-verfae termino amp; applicata interceptis , comprehen-fum.

Sit in Hyperbola BCD, cujus Aftymptoti A E, A F, dult;fta

diameter utcunque PACN, cujusfecundadiametertranfverl* P C conjugatafitG C H, parameter verb CI, ipfis nempe P C,

G H tertiaproportionalisjSc fit ordinatim ad didtam diametrum

appli-

-ocr page 225-

• Lib. I. Cap. II. nbsp;nbsp;nbsp;197

applicata quselibet D N: dico efle ut G H quadratum ad C P quadratum, aut, quod idem eft ‘, ut redia I C ad rcótam C P, ita ,nbsp;nbsp;nbsp;nbsp;^o-

quadratum D N ac P N C redangulum. nbsp;nbsp;nbsp;nl. lo

Produdda enim applicata D N utrinque per Hyperbolam Afymptotos, ut E B N D F, cum lit ^ F N quadratum ad H C *p«‘4,nbsp;quadratum, ideft^ ad BFD reftangulum, utN A quadratum^

adCAquadraturntf*quot;'-eritdividendo'^D N cw. d quadratum ad H C hujut.nbsp;quadratum,ut PNCnbsp;nbsp;nbsp;nbsp;f'

Kdangulum «

C A quadratum t Sc ^ per 6 permutando ® D 'i^fecutidi.nbsp;quadratum ad P N Cnbsp;nbsp;nbsp;nbsp;* **

refl:angulum,utH C quadratum ad CAnbsp;quadratum, five^ut^feriynbsp;G FÏ quadratum adnbsp;C P quadratum , aut,nbsp;quod idem eft, ut ICnbsp;ad C P. Quod de-monftrandum erat.

Corollarium i.

. nbsp;nbsp;nbsp;Hinc colligitur ,

quo pafto dats cujuflibet HyperboI«,ut BCD, Afymptoti inve- s pey 7 uiantur. Quippeinventis ®centro A, diametroquacunque AN cmll.snbsp;qu* curvam fecet in C, amp; ordinatim ad eandem applicata B N; ft,nbsp;produftaN A adP,ut A P ipfi A C fit aequalis,du(ftaqueper C re-•fta G CI applicats B N parallela, in eadem notentur punda H Scnbsp;PjitautfitPN Cre6i:angulumadBNquadratum,ficucA C quadratum ad quadratum abs C G feu C FI: erunt, qu« ex A centronbsp;per G amp; H ducuntur reamp;x A G E amp; A H F,Afymptoti qusfita 9.9 per cmh

nerfum

Corollarium. t.

Ex demonftratis patet, fi per P amp; I tranfverfae diametri para-*Betrique tcrminos ducatur reda PIK, occurrens cuUibet appli-

B b 3 nbsp;nbsp;nbsp;cats;,

-ocr page 226-

198 Elem. Curvarum

catae,utN D, produdsjfi opus fuerit, in K: redangulum C N K

I per 10

hujus

conv.

» per 4 fexti.

quadrato applicatx ~nbsp;nbsp;nbsp;nbsp;D N sequale efle.

3 per i fexti.

* per 9

gt;l/-

Quoniam enim eft ‘ ut P C ad CI , fivenbsp;ut P N ad N K ^, idnbsp;eft , (fumpta N Cnbsp;communi altitudine)nbsp;ut P N C redlangu-lum ad C N K re-«ftangulum ^, ita i-dem PNC redian-gulum ad D N ^qwa-dratum , erit re^nbsp;öangulum C N Knbsp;quadrato applicatasnbsp;D N squale, id eft,nbsp;fi veterum Geome-' trarum moreidpro-poni placeat:

Qux ab Hyperbola addiametrumordinatimapplica-tur, poteft fpatium adjacens latcri redto , latitudinetn habens lineam, qus a diametro abfcinditur inter ipfamnbsp;applicatam amp; diametri verticem interjedam, ^excedens-que figurft fimili fimiliterque pofita ei , quse lateribusnbsp;tranfverfo reéloque continetur.

CoroUarturn 3.

5 nbsp;nbsp;nbsp;per 10nbsp;hulas.

6

quinti.

Manifeftum quoque eft ex detnonftratis, in Hyperbola appliquot; catarum quadrata ad fe invicem efle, veluti redangula fiib inter-ceptis diametri portionibus, ab utroque tranfverfae termino fttni-ptis, ut, fi applicate fint LM, D N,eritutquadratumLMadnbsp;reftangLilumPMC,itaquadratumD NadrecftangiilumPNC;nbsp;cum utriufque eadem fit ratio, quse eft parametri ad tranfverfatu

diametrum 5, eritque propterea ^ permutatim L M quadratutn ad

per 16 jp quadratum, ut P M C redangulum ad P N C reólangulum. wnu.nbsp;nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;0nbsp;nbsp;nbsp;nbsp;Theo-

-ocr page 227-

Lib I. C A ]?. ÏÏ. nbsp;nbsp;nbsp;jfpp

Theorema X.

Tro^qfitio ii.

Si quslibet contingens cuicunque Hyperbolas diametro occurrat, atque a punfto contaélus reda ad ean-dem diametrum ordinatim applicetur, crit recflangulum fub diametri portionibus a centre per contingentemnbsp;applicatamque abfeiflis squale femidiametri tranfyerfaenbsp;quadrato.

QyamcunqueHyperbolamK C,cujus Afymptoti AD, AF, contingat inpunfto Cutcunquefumptorelt;5iaE CF, Afympto-nbsp;nbsp;nbsp;nbsp;'

tis occurrens in E amp; F, diametroautem AH utcunquamp;duflje

inij amp;perpunftumcon-tadus C ad eandeni dia-inetrum ordinatim appli-catafit CH, quxprodu-da Afymptoto occurrat in M. Dico redangulumnbsp;HA Itequalefore quadrato femidiametri K A, five,nbsp;quodidemeft*, continue I7nbsp;proportionales elTe H Anbsp;KA,amp;IA.

Dudis enim DKG ap-' plicatsCH, amp;KLcon-fingenti F E parallelis, notatoque interfedionis pundo R, cumnbsp;fit^ RCadCF,utRKadKD,hoceft^MGadMF,nbsp;LEadLD; erit quoque ¦* M G ad G F, ut L E ad E D. Qua-

cum porrb ^ fit F G ad G A, utD EadE A: erit® ex aequo jus.

^G adGA,ideft7,HKadKA,utLEadE A, hoc eft®, ut^P«r x

adl A; amp;®componendoH AadKA ,utKAadI A. Quod^^^^' jnbsp;nbsp;nbsp;nbsp;fnbsp;nbsp;nbsp;nbsp;—^4 percont-^

'^emonftrandumerat. nbsp;nbsp;nbsp;pofttio-

rtem ration's contrariam , vide Clavium ad 18 jttinti- 5 ^tr p hujus, ^ per 2% quinti. 7 per i fixti. t‘r 2 fexti. 9 peri^ epuinti,

Theo^

-ocr page 228-

iOC?

Elem. Curyarum

Theorema XL

IX.

Tropofitio

Si quaelibet contingens cuicunque fecundae Hyperbo^ les diametro occurrat, atque a pundo contaftus redanbsp;adeandem diametrum ordinatim applicetur, erit reftan-gulum fub fecundae diametri portionibus, a centre pernbsp;contingentem applicatamque abfeiffis , aequale femi-fecundae diametri quadrato.

Quameunque Hyperbolam K C, cujus Afymptott A D, A F, contingat ia punflo C , utcunque fumpto, reóla F C occur-rens fecundae diametro A B, utcunque duólx in Qj dico, fi ex C

ad eandem diame-B nbsp;nbsp;nbsp;trum A B ordina

li

tim applicetur refta C B, amp; ex A eidemnbsp;aequidiftjns ducaturnbsp;A K H, fecans con-/V' \nlnbsp;nbsp;nbsp;nbsp;tingentem F C Q,

• nbsp;nbsp;nbsp;7

hujusi

in IjHyperboteque occurrens in K , at-que per K rc(5ta a-gatur DKG ipl*nbsp;AB parallela, (itanbsp;ut ‘ A KH diameter fit fecundx diametro A B conjuga-ta, ac femi-fecund«

diametri magnitudinc fintKGjKD,) fore rcdangulum B A Q. aequale ipfius K G vel K D femi-(ecund$ diametri quadrato.nbsp;Duda enim per C reda T C M fecundx diametro A B paralquot;nbsp;^ ideoque ad interceptam diametrum A K H ordinatim appH-Hyperbola occurrat in T diametroque A H in H, A-3 fgt;tr 4 fymptoto verb A F in M : Quoniam eft ^ H A quadratum adnbsp;^ K A quadratum , five ^ H. M quadratum ad K G quadratum

-ocr page 229-

L t B. I. C A P. It nbsp;nbsp;nbsp;zót

feu’adTM Creétangulum, utH AfeuCBadI A,ideft^, ut i B Qad A Q;crit dividendo ^H CquadratutnfeuB Aquadratumnbsp;ad K G quadratum, ut B A ad A Ac propterea ^ B A, K G,

A Q^proportionales erunt, redangulumque B A quadra- fexti. ^ to K G asquale. Quod demonftranuuin erat.nbsp;nbsp;nbsp;nbsp;i per ij

quinti.

Corollarium ad duas ^ro^o^tionesfracedentes. nbsp;nbsp;nbsp;“ cw.

Ex diélis facillimè colligitur, quo pafto a dato quolibet punóio * per 17 ducenda fit refta, qu£E datam Hyperbolam contingat.nbsp;nbsp;nbsp;nbsp;fixti.

Si enim datum pundum in ipfa curva fit, veluti K, inrentis A-iymptotis dud^ue ad illarum alterutram reda alteri Afympto- ® nbsp;nbsp;nbsp;*

to parallela, ut K P,ac fiimpta P G ipfi A P squali, continget jun- nbsp;nbsp;nbsp;’ °

da G K D Hyperbolam in K quoniam uti G P ipfi P A, ita G K 7 quot;per 6 ipfi K D aequalis cftnbsp;nbsp;nbsp;nbsp;hujus.

Eodemmodo, fi datum pundum fit in Afymptotorum alteru-* tra,yeluti G,divisa A G bifariam in P, dudaque P K alteri Afym-ptoto parallela , qus curvx occurrat ^ in K : continget junda ^ P‘'‘ ^

G K D Hyperbolam in pundo occurfus K.

Sit deinde datum pundum intraangulum Afymptotis com-prehenfum, veluti I:duda a centro“ per I diametro, ut AlH, fexti, é-qus curvs occurrat in K, fumptaque A H ipfis AI, A K tertia ^ proportionali, fi per H agatur ordinatim applicataHC ( nimi-p”™”quot;nbsp;rum, quxeontingentiinKsquidiftet ^),occurrenscurva2in C,clt;)r5/. 7nbsp;continget junda I C Hyperbolam in eodem C pundo.nbsp;nbsp;nbsp;nbsp;hujuj.

Sit denique datum pünótum in alterutro angulorum, qui dein-ceps funt, angulo Hyperbolam continenti, veluti Qj duda per Q^huj'us-^ centrum A fecunda diametro Q^A B, tranfvers^ue ipfi conju- '^perii %ïta A K H (nimirum, quae produda qüamlib^t redam in Hyper-^ola dudam ipfi QA B atquidiftantem bifariam dividat), nee nonnbsp;*^ngente KG velKD, Afymptoto terminata; fi fiat quadratonbsp;^G vel KDtequale redanguIumQ^AB, acperBadfecundamnbsp;diametrum AH applicetur reda BC, nempeipfi AKtequidi-ftans“*, quxcurvs occtjrratinC: jundaQ^C'Hneodempun- 14 ^^^7

C Hyperbolam continget.

Manifeftum porró cft, fi datum pundum vel intra Hyperbo-^ lamforct, vel intra angulum ad verticem ei, qui Hyperbolamnbsp;continet; fieri non pbfle '®, utabeodem pundoducaturreda,

^U£ produda eandera non fecet. nbsp;nbsp;nbsp;^

Cc


Ca-


-ocr page 230-

X02f

C A P U T 111.

DEFINITIONES TERTI-®.

I.

SI quodlibet trïanpuli reftanguli latus, five id re^lum angulum fubtendat, five acutorum akerutri oppofi-tum fit, in eodem angulo moveatur, ita ut uterque mo-ti lateris terminus femper exiftat, maneatque in latere,nbsp;cui ab initio junftus fuit, prodiuko ramen five ab alteranbsp;five ab utraque parte, prout opus fuerit; idemque illenbsp;motus tam per angulos , qui praefato deinceps funt,nbsp;quam per eum , qui ipfi ad vetticem eft, ordine con-tinuetur ,¦ donee ad pofirionem fitumque priftinumnbsp;latus motum redierit, atqiie ita quolibet pundo quodnbsp;in eodem , utcunque etiam produfto , notare placue-rit , curva defcribatur linea , praediekum mobile latus^nbsp;T)efcribentis Line£ nomine defignabitur.

I I.

Punftum autem quod in eodem ad defcriptionem notare placuerit, TmSitm Efficiens, aut ‘Punbfum fim-pliciter vocabitur. _

I I L

Diftantia verb ejufdem punifii tam ab uno quam ab al* tero defcrïbentis termino Intervallum dicetur.

I V.

Cumde angulo fimpliciter fermo erit, eum inrelligC' mus, quemfubtendit, amp;inquomovetur defcribens.

V.

Anguli vertex , quem deferibeni continuato motu quafi circumambulat, Centrum appellabitur. ^ ^


-ocr page 231-

10|

Lib I. Cap: III.

VI.

Alterutrum anguli crus, utrinque, fi opus fuerit, pro-duftum, atque ab utraque parte a. Qentro fumptum, ma-gnitudine intervalli in altero crure termiiiati Direöirix vocabitur.

VII.

‘Defcribentemin flationeprima, cdmeaad direSfricem eft perpendicularis; idem autem amp; tunc dcnbsp;pun£ïo didum efto, accum deiis fimpliciter fermo eritnbsp;in ea ftatione confiderabuntur.

V 11 r.

Reda ^pundio per Centrum duda, intercepts inter punöiumamp;centrumèMif^'è., Secans nuncupabitur.

Ut fi trianguli reöanguli ABC Irftus B C moveatur in anguh B A C, ex. gr., ut terminus C tendat ad A, fimulque B vel retro-cedatvel promoveatur versus I; ka tarnen, ut iidem termini B amp;nbsp;C femper lint amp; exadè maneant in later ibus, quibus ab initio

Bg.\.

in latere A B, ac C in latere AC, produdisnbsp;ubi opus fuerit; eo-demque illo motanbsp;quolibet fui pundo»nbsp;ex. gr., H, aflümpto,nbsp;prout placuerk, livenbsp;in ipfa B C, live in ea-dem produda , ( ut anbsp;nobis plcrumque af-fiimetur ,cum id nature quodamfnodo con-Venientiüs videatur,)nbsp;defcribat curvam li-

jundiruêfe, nempeB

Beam: nempc, ut, ubi pundum C pervenerit ad A, ac pundum B I, fimulque H procelTerit ad F, defcripta fit per raotum ptindi

C c a nbsp;nbsp;nbsp;H cur-

-ocr page 232-

2.04 Exem. Curvarum

Hcurvar portioHF: deinde pun6lo C promote per A ad M, fiquot;* mulque termino B retrogreflb vel progreflo ab I ad K , ita ut H

pervenerit ad L,defcriptus fit arcus F L: eodemque mode, ubipunctum B pernbsp;K continuato motu pervenerit ad Ajfi-mulque pund:um C per M progredien-do pervenerit ad Q^, ac punöumnbsp;ill H in Einciderit, deferiptus fitarcusnbsp;LE: a‘c rurfus ubipunftum B per Anbsp;progreflum fuerit ad N, fimulque pnn^nbsp;dtum C ex Q^vel retrocefferit vel pro-grefium fit ad O, ita ut tunc pundamnbsp;H pervenerit ad P, deferiptus fit arcusnbsp;EP: atque 11 porro eodempadomo-tus ille continuetur, donee prsdidumnbsp;punftum per G amp; D tranfieritrurfuf-guead Hpervenerit, deferiptafittotanbsp;curvaHFLE P GD : eruntnbsp;B C, quas amp; in aliis ftationibus eftIA„KM,AQ^, NO» amp;c.

lined deferibens.

H pmbtHm efficiens.

H C amp; ti B utrumque intervallum.

Anguli vertex, nempepundumA, Centrum.

Etfi altcrutruM mgti^ crus,exempli gratia, A C»nbsp;utrtnque, fi opus fuerit,nbsp;produdum fit, velutiadnbsp;D amp; E j ita nempe, ut tamnbsp;A D quam A E sequalis fi*^nbsp;redae H B, intervdlo viquot;nbsp;delicet, quod in alteronbsp;crure terminatur , tot*nbsp;D E direblrix erit.

Cum autem defiribent B C eidem direSlrici D Enbsp;eft pcrpendicularis, quod quidem fit, quando ipfa pofitione ea-dem eft cum crure AB» utiAI, nempe exiftente redo.


-ocr page 233- -ocr page 234-

-2,c5 Elem. Curvarum

Fig. I. nbsp;nbsp;nbsp;Bg. 11.



, per Ij;' gulum, ita L M quadratura ad L K quadratum, hoe eft, ita F A ^uinti. quadratum ad A E quadratum, five ' ut F G quadratum ad D E

quadratum,con-fs nbsp;nbsp;nbsp;Hnbsp;nbsp;nbsp;nbsp;^ ftat priori cafu

propofitum.

Non fit dein'* ^e angulus B A Cnbsp;reftus^, ducan-turque ad dire-'nbsp;Slricem, eamvenbsp;produdam , ^nbsp;opus fuerit, re-Ftx K O , L Pnbsp;defcribenti B Cnbsp;parallelas, ideo-

que ad di-reSlricem D E perpendiculares, ut amp; IN lateri A B pa-^ rallela, quae ipfi LP, eidemvèprodu’dje, fi opus fuerit, occur-^ 5 ita Ut quot; fimüia fint triangula AHC amp; ILP, item-

que


-ocr page 235-

t I B. I. C A P. III.


aof



1/ P


F^.n.


N'


LI, amp; ita BA ad N I, ac pernbsp;confequcns BA.nbsp;ad K A , ut ea-dem B A ad NI:nbsp;erit ® K A ip- * per 9nbsp;fi N I tequalis.

Sunt autem amp; parallels, exhy-pothefi. Qua-re amp; AI, KNnbsp;squales amp; parallels enint L 33jnbsp;Porro cumnbsp;quales fint re-ös K L amp; A Enbsp;vel AD , ideo-que amp; ipfarumnbsp;quadrata , hincnbsp;fubduélis ab iisnbsp;squalibus, qua-drato nimirumnbsp;K N ab una ,nbsp;ac quadrato AInbsp;ab altera parte,.

eraut.


-ocr page 236-

io8

Elem. Curyarum

Fig. VII.


‘^«¦47

frimi, amp; ƒ femndi.nbsp;* per 4 dï*nbsp;ai fexti.

3 per fk-fra de-taonjh.

^per if

jitinti.

crunt quoque refi-* dua,quaclratum nemquot;nbsp;pe L N amp; reélanquot;nbsp;gulum DIE squa--lia '. Unde cum fitnbsp;* L I quadraturn adnbsp;LN quadraturn, hoenbsp;eft ^, ad DIE re-öangulum, ut A Hnbsp;quadraturn ad H Bnbsp;quadraturn , id eft»nbsp;ad AE quadratunv»nbsp;five ^ ut H G qua-dratum ad D E qua-dratum , erit etiaiunbsp;hoe cafii propofituH*nbsp;manifeftura.

Atque ita liquet, prsedirflam curvam eam ipfam eflé. qute Veteribus Ellipfis difta fuit, dire^rkem verbacnbsp;fècantem eas ipfas, quas corijugatas diametros, aut,nbsp;angiilus reftus fuerit, conjugatos axes voc^runt.

Conjugatas itaque diametros appellabimus biiiaS rclt;5las per centrum duöas, acutrinqueEllipfitermi natas j

-ocr page 237-

L I fi. ï. Cap, III. nbsp;nbsp;nbsp;2,09

fas; itaut(quemadmodumdedfzgt;^if?rifÉ’i8c fecante]nm ‘iemonftratum eft,) quadrata redtarum qujE alteri ipfa-rum applicantur alceri jEquidiflant, ita fe liabeant adnbsp;reftangula fub partibus per applicationeni faftis , utnbsp;quadratum akerius adquadratum ejufdem quK per ap«nbsp;plicatas fecatur.

Et hjec quidem, cui applicate inliflunt, ttanlVerfa; illa verb, cui eaedem sequidiftant, fecunda diameter vo-cabitur.

Caeterae autem omnes , per centrum .duftje ac u-kinque Ellipfi terminatae , diametri fimpliciter di-centur.

Redtam lineam quae tranlvérfae fecundsque diametro tertia eft proportionalis, Latus Redlumfive Para-qietrum vocabimus ad tranlVerfam diametrum perti-nentem.

Notandum tarnen efl, ïi angulus redtus fit, ac pm~ cium ab utroque defcribentis termino asqualiter diftet,nbsp;curvam, quse motu ejufdem punbfi, utipraedidluni eft ,nbsp;defcribitur, circumferentiam Circuliefle.

Corollarium. i.

Ex ipfa demonftratione amp; collatione priifl* cum fecun-da manifeftum eft; inEllipfi, conjugatorum axium tranfverfurrt ^ftam fecundum efle, amp; contra. Sive enim LI velhüic velillinbsp;applicata fit, eodem modo femper probabicur efle quadra-ejufdem applicatse ad rcdangiilum fub partibus axis cuinbsp;^Pplicatio fii , ut quadratum axis akerius ad quadratUm axisnbsp;Pf^didti qui per applicatam fecatur.

Corollarium i.

Apparet porrb rcftam per pumftum dudam nbsp;nbsp;nbsp;paf alle-

hoe eft, eam, quse per terminum fccunds diametri tranf*

D d nbsp;nbsp;nbsp;verf*

-ocr page 238-

2,1© Elem. Curvarum

rerfe xquidiftans ducitur , EHipfin in eodem termino , amp; itt nullo praeterea punclo contingcre, raultó minus eandem, lica-



« incafü nbsp;nbsp;nbsp;enim per F ^ aut H * terminum fecundae dlametri GF^

fig. I amp; vel G H * duóta reéta S T , tranfverfae diametro D E paralle^' limilib.

* in cafti Jimilibi

lE, aflumatur aliud quodcunque in curva pundlum, velutl L, quod defcripwntfit deftribWi in ftatione K- M , ducaturc^*

-ocr page 239-

L I B. I. C A P. III. nbsp;nbsp;nbsp;ill

Li quot;vellp ^adtranfverfamdiamctrum perpendiculans, fietut* in cafa criangulo MLPvelMLP ‘reélaML, ideft-, perpendicula-ris F A “ vel H C % major fit ' quam LI “ vel L P *; adeó ut pun- ^3(9nbsp;lt;S:umL,quodmcurvautcunqiieafiumpturtieft, id eft, totaEl- figingcnbsp;ftpfis, prsEtcr F “ aut H‘pundum,infradutftaraST, feu versus fimilib.

Lllipfeos centrum, cadat-. nbsp;nbsp;nbsp;^ per 1%

*¦ nbsp;nbsp;nbsp;pnmU

Corollarhim 5.

Manifeftum quoque eft in Ellipfi applicatariim quadrata ad fc ^nvicemeffe, utredlangula fubdiamecri portionibuspcrapplica-tas faflis. Ut fi applicate fint LI,nbsp;nbsp;nbsp;nbsp;critquadratum quot;WX

3d reclangalum D X E , ut quadratum LI ad redtangulurn DIE: cum ^ utriufque ratio fiteadem qujequadrati F G“ velH G Gd ^per ijnbsp;quadratum D E, five quse parametri ad tranfverfain diametrum jnbsp;idcoque amp; permutatim WX quadratum ad LI quadratum, utnbsp;L) X E rectangulum ad DIE roftangulum.

Corollarium .

Conftat etiam ordinatim ad a'xem five diametrum applicatas Utrinque adEllipfin produftas ab axe five diametro bifariam fc-(Jt, k applicata LI produdta Ellipfi occurrat in V, quoniamnbsp;fft ’quadratum LI ad rcdlangulum D IE, ut quadratum V1 ad 3 psrcor.nbsp;’dem DIE rcétangulum, erit '•quadratum LItequalequadrato priced.

^ I, idcoque amp; ipla redti LI ipfi reda: VI tequalis.

Corollarium 5'.

Conftat porrb, applicatas Ellipfi in pluribus quam duobus PUndis non occurrere. Si enim L IV aliofuipundo praitcr L amp;nbsp;ygt; exempli gram, pundoZ, in Ellipfi efl'et, redae t Lamp;I ZA, ^ pwCar.nbsp;jdeoque IV IZ pars amp; tocum, squales forent, quod eft ab-^^rdum.

Corollarium é.

Lx didis porró colligitur, fi ab extremitatc tranfverfiedia-

D d 2 nbsp;nbsp;nbsp;raetri.

-ocr page 240-

fig- I 8c (imilib.

IJV E L E m! C « R V a r. u m •» in ca/li metri, ut puta F Gquot; , edufta parametro F S fecundae diametronbsp;DE parallela, jiingaturSG, atcjuead eaademdiametrum refla

% I.


^Hslibet ordinatim applicetur, utRQ^, qusfecetjun(5i:am S G ill Y: fore reftangulum F Q.Y quadrato applicate R Q^squ^Ie*

»15 hujus.

-ocr page 241-

L I B. L C A p. III.

per 9 qttinti.

V Q;Freftanguluin,ut * idem G QF redanguIumadR Q^qua- ' pen^ dratum^SEquatiaeruntnbsp;nbsp;nbsp;nbsp;C^F rcSangiilum ad. K Q^qaadratum:

id eft, ft veterum Geometrarum more id proponi placear.

Qu£b ab Ellipfi ad diametruni applicatur poteftfpa-tium adjacens lateri re(R:o , latimdinem babens lineam quae a diametro inter ipfam applicatam amp; diametri ver-ticem abfcinditur , deficiensque figura fimili fimiliter-que pofitft ei quae lateribus tranfverfo reéloquc coU'»nbsp;tinetur.

Corollarium 7.

Patet quoque ex antedidtis , quo padlo, datis quibuflibet dia-metris conjugatis, Ellipfis in piano defcribatur.

Ut ft conjugatis axibus DAE amp; FAG *ElIipftsftt defcri-

deferibente B C, qu£E femi-axium A D, A F differentia ftt,quot; in cafci intervallis verb FJ C, H E, ipfts A F, A D utroque utriquetequali-bus, inlt;a;2^WoD A G, curv^adefcribatur,eritquehsEC ipfaEllipfts

qujellta.

At ft aliis quibuflibet conjugatis diametris,.obliqueFefe inter-fecantibus, ut D E, H G % Ellipfts ftt deferibenda; demifsa a ter- ^ In cafa mino unius ad alteram perpendieulari, ut H C, fumptaque in ea- ^.8^ ^ ^'nbsp;dem feu in ipfa produdla, ft opus fuerit, redla H B ipfi D A vel *™i^**’

A E jequali, amp; per B amp; A dudta reeia B A F, ft deferibente B C, in~ tervalUs veroH C, H B, in angulo BAG Ellipfis defcribatur, ericnbsp;hare ea ipfa quar quarritur.

Itaque cum datis diametro parametroque , nec non angulo quern faciunt cumeadem diametro ordinatim ad ipfam applica-tjB, conjugate quoque diametri dats ftnt: fimul quoque inno-’nbsp;telcit, quo paeffo amp; illis datis Ellipfts defcribatur.

T H E O R E M A XIIL

Trofojïtio 14.

In Ellipfi circa quofeunque axes deferipta, du61a qnx-libet diameter tranfverfa eft, habetque fecundam fibi conjugatani.

D d nbsp;nbsp;nbsp;Sit

-ocr page 242-

XT4 Elem. Curvarum

* per ^ primi.

Sit in Ellipfi S Y X Z, cujus centrum A, axes vcró S X, Y Z, dult;3;a qua:libet diameter D A E; amp; fic dcfcribens O in ca fta-tione, uti fuit cüm defcriptum eft pundliim D vel E, ita ut inter-valla liat D W, D O. Deinde applicata cadem defcribente in fta-tionc reciproca, hoe eft, in alterutro angnlorum qui ipli quot;W A Onbsp;dcinceps funt., veluti P R, ita ut redte A R, A P iplls A XZ, A Onbsp;reciprocè fint3cqualcs,nimirum AR ipfi A O, amp; A P ipll A W,nbsp;ac proinde triangulum XZ A O ' ftmile amp; squale triangulonbsp;PAR, ab Ellipleos punéto H, quoddefcribenti PRindirc-dumeft, duda fit diameter alterati A G. Dico diametrumD Enbsp;tranfverfam efle, H G autem fecundam ipfi D E conjugatam: id.nbsp;eftj fi, dudaH C ad D Eperpcndiculari., in eadem H C, produ-


^ per hujusnbsp;ejusquenbsp;Corol. 7

• autcer-tè, quia punefto-rum T

da, ft opus fuerit, fumatur H B ipftD A scqualis; dud^'aeper B amp; A reda B A F, in angulo B A C, intervallis verb H C, H B,nbsp;Elliplls defcribatur.CLijns utique conjugats diametri funt in D E,nbsp;amp;HG^: clicoillam cumexpofita Ellipfiomnino eandemforcjnbsp;ita ut altera alteri per omnia congruat.

Aflumpto enim in expofita Ellipfi alio quopiam pundo L, qviod quidem defcriptum fit defcribente in ftatione T V, diametro TV circülusdefcribatur, qui, propterangulumTAVre-dum quot;, necelTarió quoque per A tranfibit ^, lincafque B A F amp;

DAE

amp; V al-

tenitrum cum pundo A coinciJit, uti ed cafus in fig. VI 3 per cen-jerfam 31 tertii.



-ocr page 243-

Lib. I. Cab. III.

* aut il-larutn al-teram-contin-get, alteram vero fccabir,nbsp;vt innbsp;calib. fig.

in amp;iy.

D ae alibietiamfecabit % utiin Kamp;M. DeindejunöaKM, eaqueproduda versusL, agamur TK, PB.

Cum igitur ipfarum D O, H P, produdarum, fi opus fuerit

interredio ad Q^fiat ad angulos redtos, ob fimilitudinetn trian-

guli O QP cumutroque tnangulorum O A W, R AP % nota-' vel, fi

to ipfarum DE, PH interfeCtionis pundo I , erunt trianguIaP“quot;'^a

. r nbsp;nbsp;nbsp;gt;nbsp;nbsp;nbsp;nbsp;» O amp;P

coïnci-dant, ofc angulosnbsp;AOW.nbsp;APRfe.-miredos-

ÏQ^D, ICH aquiangula, obangulosad Q^amp; Credos, adl Verb aut communem aut ad verticem. Ideoque cum triangulanbsp;C D A, P H B latera O D, D A lateribiis P H, H B, utrumquenbsp;tttrique, circumjequales angulos«equaliahabeant: eritamp;' balls’4^

-ocr page 244-

¦prinu.

t per 4 primi.

Elem. CurvarUm O A, liveredta A R, bafiP B, anguIusqueD O A, ideftPR A,nbsp;^pn^^ angulo H P B sequalis; acpropterei ‘ reétaPBipfi RAparallc-la. Hinc cum triangulorum RAP amp; B P A lateraR A, A P la-teribiisBP, PA circa tequales angulos, nempe reci;os,ütrumquenbsp;utrique fmt tequalia: ent amp; ^ balts A B baH , feu defcri-benti TV, angulusque A R P angulo P B A trqualis. Quocircanbsp;amp; circulus diametro A B defcriptus (qui quidem, obangulosnbsp;ACB, APBreétos, aeABP, ARPajquales, perpunftaC,

3 nbsp;nbsp;nbsp;per con- p 3 ^ amp; R 4 tranlit) circulo T K V asqualis erit. Unde cum an^

P B C, B P R ipfis T K M, K T V, uterque utrique, aiqua-

4 nbsp;nbsp;nbsp;per con- les fint, nempe P B C ipfi T K M , quoniam iSerque cum an-'uerfam pulo'P AC feu T AM binosredlo^cottftituitquot;, amp;BPR ipli

ii tertii. °

* procafu fig. II adde; ideoque 5c hi qui ipils deinceps funt. ? pern tertii, ' in calli fig.II uterque angulo PAC feu T AMtequaüseftpsr lotfytó. Incafufig.III uterquenbsp;Cum angulo PA C binos reftosconftituit,nempefaic per i jprimi, amp; ilie per^^ tertii. Innbsp;Cafu fig. IV Kquales funt anguli P B C , T K. M , quoniam prior cum angulo PAC, pofte-rior veró cum angulo T V A (qui quidem P A C, T V A aequales funt per 31 tertii) binosnbsp;re6tos conftituit periitertii. Incafu fig. V, T K M fi?eT AM aequaliscft angulo PBC,nbsp;quiautecque cum angulo PAC duosreftos conftituit psr primi df io aciztertii. Innbsp;cafu fig. VI sequales funt anguli P B C, T K M, quoniam angulus PAC stqualis eft ei, quinbsp;infegmento A VM conftitiieretürpsr 31 twir, quorum quidem prior cum angulo PBC,nbsp;pofterior verd cum angulo T K M binos redlos conftituit perzz tertii.

¦E...

per io tertii, atnbsp;que innbsp;cafu fig.nbsp;Ill pernbsp;eandemnbsp;5c 3 1 tertiinbsp;cum

KTV, propterea quód uterque ^anguloBAR feuKAVfivfi F A V squalis eft^quot;; fintque porro, ob aequales angulos P AB *nbsp;T A K ^, tam periplicriae P B, T K, quam earum fubtenfx, nemquot;

pC

cm nbsp;nbsp;nbsp;.

'¦ tertii. tin cafibus fig. IV 8c V tam angulus B P R feu B A R, quam angulus KT*quot; angulo K A V duos reólos conftituit per 13primi,tertii. 7 per z6 amp; z^ tertii. .

-ocr page 245-

Lib. I. Cap. HI.

pc latera P B, T K didis sequalibus angulis adjacentia inter fe ^ualia ^ : apparet ficuti red* B C, P R produfta: concurrunt *nbsp;in H, ita quoque redtas K M, T V produdas, amp; quiolem , cum bfreSa^'nbsp;ipfi P H ^qualis fit T L , in ipfo pundo L concurfuras. quippe B A Fnbsp;cx antedidis ‘ fimilia atque in totum aequalia funt triangula «“g'tnbsp;B P H, K T L, adeoque amp; latus K L lateri B H £equal^ Eft au-tern * amp; fubtcnfa KM fiibtenfie BCiequalis*, obasqualesan-^quaUj

funt latera B P.TK.oBangulosBAPjT VKscqualesfer51 terlii. Incafufig.VI,ubireftaP AY contingit circulumTK V, atqualesfunt fubtenfeB P,TKobangulosP A B, TMKsc-^Vdles pertertii. ¦ periópnmi. ^ peri6 ér ^9 tertii. ^ Incafu fig. III, K M ipfiBCeftnbsp;*qua!is, quandoquidem angulus qui confifteret in fegmento KT M tequalisforet angulonbsp;Pam feu B A C per 3 z tertti. In caiU fig. IV, K M ipfi B C eft xqualis , quandoquidem angulus K T M aequaliseft angulo K A C feu BAG per 31 tertit. Incafu fig. V, KM ipfi B Cnbsp;eft squalls, quandoquidem angulus in fegmento B C squalis foret angulo K A M, utpotenbsp;, cum tarn iiic quam ille cum angulo CAB duos redtos conftitueret per 13 primi ^zz tertii.

gulos KAM, BA C. Quocirca Sc LM ipfi HC squaliserit.lt; ut In Cnde cumdcfcribensfitKM, utpote ipfiB C atqualis, accon-‘^®^“%-ftitutain angulo KAM (qui cum ipfo B A C velidem’, veleiadif ¦nbsp;vertieem ^, vel denique ipfi deinceps eft ' ) aut certe cum al- cafibusnbsp;’^crutro crurum coi'ncidens , atque ex demonftratis jeqiialia %-f amp; ft-lt;lUoque fint intervalla HB, HC intervallisLK,LM: fequi-^nbsp;pundum L, in expofita Ellipfi utcunque fumptum, id eft, «^ut^knbsp;^'^tam Ellipfin S Y X Z, efie in Elbpfi, qua: in angulo BAG, in- cafibusnbsp;^'tvallisHB, HC, deferibitur , ideoque aiterara alteri per % * W’

¦ Ee nbsp;nbsp;nbsp;—

-ocr page 246-

ai8

Elem. Curvarum

8 per IJ iujus,nbsp;ejufquenbsp;Cor. f.

omnia congruere. Sunt autem ’ hujus conjugate diametri D E » HG. Qaare amp; illius, c^usecum ipfaeademeft, conjugatse dia-

metricrunt, nimtrum DE tranfverfa', amp;HG fecunda. Qao£ deiRoaftrandum erat.

CoroUarium. i.

Hinc colligitur non folum ElEpfes omnes fuos habere axes,, fed amp; quo paóto datis quibuflibet diametris conjugatis ,ejusElU'nbsp;pfeos cüjus diametri funt, axes inveniantur.

Utficujufcunque Ellipfeosconjugatie diametri fintD AEamp; H A G, duda H B, femidiametro D A vel A E a’qnali, atque adnbsp;D E perpendicular! , jundaqueB Aac ipsabifariaminN divisa»-fi centro N intervallo N AvelNBcirculus defcribatur, fecansnbsp;redam per H amp; N dudam in P amp; R: erunt reds HP, H R flt;^nbsp;mi-axes magnitudine,qus idcirco utrinque a centro A versus,nbsp;perpundaRamp;P, squalilongitudine indircdumpofits, ficutnbsp;tots S X amp; Y Z, exhibcbunt magnitudine ac pofitione qusfitoS'nbsp;axes ejufdem Ellipfeos, cujus D A E amp; HA G conjugats diamc^nbsp;tri exiftunt.

^ptr^

3 per j 1

DudaenimPB, fumptaque AO ipfi A K, ideoque*amp; du** dsP Bsquali, agaturD O, occurrensipfi SX inW. Cumit^nbsp;que ob angulum ACB redum defcriptuscirculusetiam pernbsp;tranfeat’,eruütangviUPBH.amp; O A D squales, quoniamute^'

-ocr page 247-

Lib. I. Cap. III.

^ue cum angulo * P A C feu P B G duos reóèos conftitiiit •. Un- « • -de cum triangula O A D, P B H latera O A , A D latcribus P B, ruiiTf^ B H, utrumque utrique, amp; quidem circa sequales angulos aqua-lia habeant; erit quoque * bafisO Dba6P H, idelt, retteeSAnbsp;vel A X, ut amp; angulus A O D anguloB P Hfeu ^ P R A tequalis.

Hinc cum aequalia Tint triangula R A P, O A quot;W,propter angu- bus, amp; los ad R amp; O sequales, atque ‘‘RAP, O A W redos, nee nonnbsp;latera R A amp; O A sequalia; erit etiam ^ latus A W lateri A P, ut^^nbsp;-flatus OXG ipfi PRaequale. Quocirca cum ^deferibentes fintincafu *

c •.•u nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;fig-II. amp;

«rtiilibus. ' fer ^rimt amp; ii fertii. * fer nbsp;nbsp;nbsp;3 perz^primi- 31i j

pfimi. s per i6primi. ^ per 13 hujus^

^ P R ejusElIipfeos, cujus axesfuntSX, Y Z, amp; quidem u* llatione reciproca conftitut* ,pitn£l(i^ue efficientia D amp; H: mani-eft ex ftjperiori demonftratione, Ellipiln, quje axibus S X ,

deferibitur, cumea, cujus diametri conjugatefunt D E amp;

^ G, omnino eandem eflè:

^rata funt, etiam cuilibet Ellipfi, amp; circa quafeunque ^iametros conjugatas deferiptae, convenire , manife-eft.

Ee s nbsp;nbsp;nbsp;Cö-

_ Atque ita, qus de Ellipfi, circa quofeunque axes de-^cripta , fuperiori Theorematp propofita ac demon-

-ocr page 248-

%lö nbsp;nbsp;nbsp;ElEM; CurVARUM

Camp;roUaruim x.

Sequitur porro ex dcmonftratione cjufdetn Theorematis, in Ellipü diametros omnes a centro bifariam fecari. demonftratirtxinbsp;cnim cft, in diametro D E, utcunque daéta,partem A E parti D Anbsp;arqualem dfe, cuna utraque intervallo H B sequalis fit.

Corollarium 3.

Patet infupcrinEllipfi , quarumcunque diamctrorum conjii-gaurum tranlverfam etianafecundam eflè, amp; contra. Ut, ft con-jugatarumdiaraetrorumDEjHGtranfverfafitD E ,amp;HGfc-


«per 14 cunda; cum inEIlipfi duÖra quaelibct diameter ' tranfverfa fitgt; habeatque fecundam fibi conjugatam ^ erit quoque H G tranignbsp;verfa. At verb amp; D E fecundam efle ipfi H G conjugatam, fafl»nbsp;collatione figurx I cum II tranfpofitis tantum litens, acmutaquot;nbsp;tis mutandis demonftratura fimul apparebit.

Corollarium 4.

Quare amp; quac per. termirlum tranfverfie diametri fecundae quidiftans feu ordjnatim applicatis parallela ducitur Ellipfii^*^

» per X Ctr.

13C per. terminum tranfverfie diametri fecundae»

T i ijuiuiuans leu ordinatim applicatis parallela ducitur Ellipfii^**' 3 eodem termino amp; in nullo prsterea punöo contingit, totaque eXnbsp;traEUipfiacadit*.

-ocr page 249-

Lib. I. C A p. III.

Corollarium 5-.


A deoque quilibet reda » a quovis cur vs punólo ad quamcun-que El'lipfeos diamctrum ordinatitn applicata, tota intra EUipfin cadit; utpotecumeanecintotumextraEllipfincadere',neeei- «per

Cor. pree-cedent.

per f


dem in pluribus quam duobus punótis occurrerc * poffit.

Theorema XIV,

Tropofitio If»

Quae bina quaelibet Ellipleos punéla conjungens re-ftalinea bifariam a diametro dividitur , eritaut per centrum dufta , autadeandem diametrum ordinatim applicata , hoceft, conjugatae diametro aequidiftans.

Si enim in Ellipil A B G D, cujus centrum K, a diametro AKC bifariam dividcrctur reéia E H G , quxnbsp;neque per centrum tranfeat, nequenbsp;conjugate diametro B D aequidiftansnbsp;fit j applicata ordinatim GIF, dudla-que per centrum reda G K L; Quo-niam eflet, ut GHadHE, itatam

GladlF^, quamGKadKL-», re- 5pw4 da per F amp; E, nec non per E amp; L du- ' 3 ¦nbsp;da foret unalinea reda diametroque ^,nbsp;A C parallela 5 j ideoque ad alteram Cw. 14nbsp;ipfi conjugatam , nempe ad B D,nbsp;ordinatim applicata ®, atque Eliipli innbsp;nbsp;nbsp;nbsp;*¦

tribus pundas occurreretj quod fie-6 ^ i j rinonpolTefupra^oftenfum eft.nbsp;nbsp;nbsp;nbsp;amp; 3 Cut.'

Corollarium i. nbsp;nbsp;nbsp;^

Coroll,

Ideoque fi diameter redam quam-libet in Ellipfi non per centrum du- ® P«-4



Cor. ij ; hujus.


dam bifariam dividatjomnesquoque 9’'' I ipfisquidiftantes bifariam fccabit« . ZjJt.nbsp;Ee anbsp;nbsp;nbsp;nbsp;Ce-»


3o

'Urn



-ocr page 250-

ARUM

I fer i Cer. 1 ƒnbsp;hujits.

ï psr I

Csr. J4

hnjus,

nliterve,

uteuilibet

cbvium

efl.

3 nbsp;nbsp;nbsp;per Jnbsp;Cor. 14nbsp;hnjus.

4 nbsp;nbsp;nbsp;per I ƒnbsp;hnjusnbsp;ejufyuenbsp;¦Cor. I.

E L E M. C U B. Y

Corollar 'mm x.

Quocirca fi inEllipfi binse qujelibet redtxfibi invicem asqui-diftantes dudae fint, qu£E utramque bifariam dividet recSa linea per iiliiis centrum tranfibit, feu ejufdem diameter exiftet. Quip-pe qusper medium unius a:quidiftantium diameter duceturpcrnbsp;medium quoque alterius sequidiftantium tranfibit ‘. Unde appa-ret, quopafto datsEllipfeos diametros quotlibet, fimulqueadnbsp;eafdcm ordinatim applicatas, nee non amp; ejuscentrum, utpotcnbsp;quod duaruni pluriumve diametrorum communis interfedtio eft,nbsp;ideoque amp; diametros conjugatas, axesque ^ invenirc liceat.

i^orollarhm 3.

Exdiftisfacileapparet, quamlibetredlam, qusebinaqujecun-que Elli^os punöa conjungit, totam intra Êllipfin cadere utpotecurnipfa** vel diameter lit, vel ordinatim applicataadearanbsp;diametrum, quse per ipfius medium amp; centrum ducitur.

Problema II.

‘Pro^ofitio 16.

In data quacunque Ellipfi du(?l«ecuilibet diametro alteram conjugataminvenire.

In data Ellipfi SYXZ dudls utcunque diametro D AE altera conjugata invenienda fit.nbsp;Inventis ’’ axi-bus SAX Scnbsp;Y A Z,atqueanbsp;termirio D velnbsp;Eadaxium al-terutrum, ve-lutiad Y A Z,nbsp;applicata re-dia, ut DO,nbsp;femi-axi alteri

SA jequali, quje piodudia, fi opusfuerit, fecet eundem axem

alte-

-ocr page 251-

Lib I. C a p. III.

altemm, utiin W, applicetur inftatione reciprocaipfi O W, cidem ajqualis redia PR, nempeutAP, AR iplisA'W, AOnbsp;finguls fmgulis jequales fmt, ac produdta P R Ellipfi occurrat innbsp;punólo H, a quo fi per centrum A ducatur reda HAG, Ellipd-terminata: conftat, perea, quaadPropofitionem i4«ninbsp;libridemonftratafunt, eandem HAG eflediametrum ipE DEnbsp;conjugatam.

Atque ita fimul apparet, fingulis diametris fuas quo-que diftinftas conjugatas diametros efle, eidemque diametro unam tantum conjugatam duci poile.

Corollarmm.

Unde porrb perfpicuum fit, quo padoper datum quodlibet in Ellipfi pundum reda ducatur, quje curvam in eodem ac in nullonbsp;alio prsterea pundo contingat. Si enim duda per datum pun-dum amp; centrum diametro, inventaquc alteraipfi conjugata ‘nbsp;per idem pundum reda ducatur inventas diametro conjugatenbsp;SEquidiftans: erit eadem reda * contingens qujefita.

Theorema XV.

Tropfitm 17.

Ellipfin in imo eodemque punfto prseter retflam, quje parallela eft diametro illi , qus per pundum amp; centrumnbsp;ducitur, conjugate, alia reda non contingit.

Contingat Ellipfin CHFG in pundo C redaDCE , parallelanbsp;diametro GH, quje conjugata fit.nbsp;diametro CF, per pundum C amp;nbsp;centrum dudx; dico aliam redant.nbsp;in pundo C eandem Ellipfin nonnbsp;contingere.

Si enim fieri potcft , contingat eandem quoque in pundo C redanbsp;ICK , diametroque LM , eidemnbsp;IC K aquidiftanti, altera conjuga-uducamrNO , (quae cum a priori

CE


-ocr page 252-

per 4 Ciii*. 14nbsp;hujus.

^ per 1 Cvr. 13nbsp;hujus.

ix4 Elem. Curvarum CF diyerfafit , pundtumNcum pundo Cnoncoïncidet,) acnbsp;perNipilLM, ideoque amp; contingent ICK, ^quidiftans du-dajitPnbsp;nbsp;nbsp;nbsp;Cadetitaque *punclumCjadeoqueredaICKinfra

redamPNQ^: nimirum, versusEllipfeoscentrum. Atveroamp; eodcmmodq ^ pundumN, ideoque reda P N Q^, infra contin-^clnU^quot; geatein ICK: nempe, versus idem centrum cadet, quod re-pugnat. NoncontingitergolC KEllipfin. Eadem de omnibusnbsp;aliis eft demonftratio, ac proinde conftatpropoiitum.

CoroUarium.

Ï per 4 Cor. 13nbsp;hujus.

4 per Co- Conftat kaque * in Ellipfi cuilibet tangenti parallelas, arqui-roU.pra- diftantes quoquecffe diametro conjugate ei, qux per tadum amp; cedeus. centrum ducitur 3 ac proinde amp; ad diametrum per tadum dudamnbsp;ordinatim applicari, atque abilia bifariam dividi^, amp; contra,nbsp;quas per cujufcunque diametri terminum ducitur squidiftans cuilibet redse, per eandem. diametrum bifariam fedsE, Ellipftnianbsp;eodem vertice contingere.

Theorema XVI.

^ropojitio 18.

Si quaïlibet contlngens praduftae Ellipfeos diametro cuicunque occurrat, atque a punélo contaftus ad eandem diametritm rcdla ordinatim applicetur: erit reftan-gulum fiib diametri portionibus, a centro per contingen-tem applicatamqiie abfciffis , femidiametri quadratonbsp;azquale, amp; contra.

Quamcunque Ellipfin G D, cujus centrum A, contingatin pundo D, utcunque liimpto, reda D E, diametro IG occurrensnbsp;in E; atque a pundo contadus D ad eandem diametrum ordinatim applicata lit D C : dicoredangulum CAE quadrato femiquot;nbsp;diametri A G squalc effe.

Sit enim primum axis diameter IG, fitque O quot;W defcrihens, in ftatione uti iuit, cum per eandem defcriptum eftpundum D ; itanbsp;ut O D intervdlutn fcmi-axi A G sequale fit, P R autcm defcnbensnbsp;biftatione, ipfiOWreciprocai itautacurv» pundoH, quod

nempe

-ocr page 253-

Lib. I. Ca p. III.

nempe defcribenti P R in direftum eft, duifta diameter H A con-jugata fit ci, qus per D amp; A duceretur', ideoque amp; contiiigen- ' /gt;«¦ 4, tiD E parallela®. Sitque porro adfecundum axem A K applied-

^ taHF,ducanturqucOE;RTfPc.r.

ipfis AG j a K squidiftantesj qu£e applicatis DC, H F, pro-dudlis, ft opus fuerit, occurrantnbsp;in B amp; T.

Itaque cumfimilia finttrian-gulaOAWamp;RAP^ erunt j quoque triangula quot;W C D amp; PruBione,nbsp;R T H , nec non O B D amp;

P F Hfimilia. Ac vero amp; la-tera W D amp; R H, nec non 5 excen-O D amp; P H ^ jequalia funt.

I E'

Quarc amp; latera WC amp; RT^g;.^ five A F, nec nonD B, amp; HF ® 7 per 19nbsp;spqualiaerunt. Sunt autem por-ro ’ triangula E D C amp; HAF *

• nbsp;nbsp;nbsp;®nbsp;nbsp;nbsp;nbsp;fextt

squiangLila j unde ex antedi-9 dis erit ® D C ad C W five triangula.nbsp;AF, id eft 9, EC ad HF fiveEDC.

D B, uti eadem D B ad B O ^

Unde cum proportionates fint J,. ECjDB, BO, erit Ut E C triangulanbsp;1nbsp;nbsp;nbsp;nbsp;ad B O five C A, ita D B qua- ^ C W,

dratum ad B O quadratum; amp;

‘^oinponendo ”, ut E A ad C A, ita' ^ D U quadratum ad B O 4?. ^Badratum, hoc eft, G A quadratum ad C A quadratum'; ac pro- '' Pquot;nbsp;inde amp; redje E A, G A, C A proportionalcs erunt, ideoque •nbsp;i^edaugulum C A E quadrate femi-axis AGarquale. Cumqueinnbsp;pBndo D alia reda prater ipfam D E Ellipfin contingere non quinti.nbsp;poffitie^nbsp;nbsp;nbsp;nbsp;converfum quoque verum efle: nimirum, fire-

^angulum CAE sequale fit quadrate femi-axis AG, amp; per C ?4^'c«.. ^r^inatimapplicataEllipfiocrurratinD, jundamEDefle con-’^^'^gentem.nbsp;nbsp;nbsp;nbsp;'nbsp;nbsp;nbsp;nbsp;'^perxj

^einde non fit reda IG Ellipfcos G D axis, fed alia diameter ^16 ij *i'^*cunque, cujus parameter IB, atque ab aflbmpto in curva hujm,

Ff ~ utcutv*

-ocr page 254-

'‘¦ptr fulgt;. demonlir.

2. per 1?.-hujus , {3 Cor. 10.nbsp;fexti.

3 per 9 quinü.

* per 4 fexti.

5 per 14 qui'/iti.

ptT 17

hnjus-.

E L E M. C U R V A R U U utcunque punéto D adeandemdiamctrumordinatimapplicetufnbsp;DC, fitque quadrato femidiametri A G aequale reótangulumnbsp;CAE: dicojundiamEDvproduöamquc, totamextraEllipfiianbsp;cadere, ideoque eandem in punélo D contingcre, amp; converfim.

Sitenimineadem ED, autinipfa produtta, proutlibuerit, affumptum utcunque punöum F, fitque per F duftaredta F H

ipE C D aequidiftans , quse didi* diametro 1G occurrat in H; EIH'nbsp;pfi veró G D in K. ( Etenim fi El'nbsp;lipfi non occurreret, manifeftifli'nbsp;mè pundium F extra Ellipfin fo'nbsp;ret.) Deinde IG utaxe, eadem'nbsp;que paramctro 1 B , inteliigatufnbsp;defcripta alia Ellipils GE, ac pegt;^

7C amp; H ad eundem axem ordina' 1nbsp;nbsp;nbsp;nbsp;'\F tim.applicenturCL, HM, quse

l\ curv£E occurrant in L amp; M, jun-gaturque EL., (qu£e utiquc Elli' pfin G L in L continget',) eaqucnbsp;produéta, fiopusfuerit, prodü'nbsp;ftse H M occurrat in N.

Itaque quoniam eftquadratuiW D C ad reéiangulum G C I,nbsp;quadratum L C ad idem G C1nbsp;(Sangulum, (quippc utriufque ea'nbsp;dein eft ratio, qu2 parametri I ^nbsp;ad diametrum live axcm I G * Onbsp;' erunt a quadrata D C, L C, ideoque amp; rediseD C, L C squak*'nbsp;Eodem modo, amp; reftas K H, M H sequales eflè, dcmonftrabiti-if'nbsp;AtverócumfitCDadHF, utCLadHN, (fiquidera‘'utriiJ»''nbsp;que eadem eft ratio,. qusc redce E C ad reöam E H,) erunt qu®'nbsp;que 5 H F amp;: H N aequales. Eft autem H N major applic®^nbsp;HM, cum contingens fic EEN: ergo amp; HF applicata H ^nbsp;major erit, ideoque pumftumF, inrcdla EDF utcunquefuiï’’nbsp;ptum, hoe eft, tota E D F, extra Ellipfin, GD cadet, five,nbsp;idem eft, eandem in punóto D continget. Cumque nonpo^^nbsp;prster EDF alia refta eandem Ellipfin in punóio D continget^^nbsp;manifeftum quoqueeft conyerfuin,: finempeED Ellipfin^.^

-ocr page 255- -ocr page 256-

Elem. Curvarum

quam a Recentioribus Locorum Inventio five Compo-Jitio appellata fuit. Ad quam promovendam, ab Apol-lonio caeterifque Geometris eaprsecipuèconfcriptaefiè, quae iii Conicorum traftatione prsdiélis Elementis fu-peraddidere , omnino credibile efl. Cumque penitio-rem curvarum linearum notitiam perfedamque earumnbsp;enumerationem ac diftinftionem, ut amp; diftributioneninbsp;in fua generaamp;fpecies, cumfegregatione earum, qusenbsp;verè Geometries non funt, ab iisqus in Geometriamnbsp;funt recipiends, ex accurata Loet traftatione imprimisnbsp;petendam exiftimem : è re fore duxi, eandem tradia-tionem hic fubjungere, non quidem ei methode , fi-cut a Veteribus inchoata videtur , cum vix integrumnbsp;amp; ingens volumen eidem fufficeret, fi vel tantum Locorum , cptx‘Plana , ac Solida (quamvis, meo judi-cio , minus redlè,) vocarunt, id eft , qus vel reBanbsp;linea, st\Parabola, ydHyperbola, vdEllïpJls, fivenbsp;circuit circumferentia exiftunt, (quorumque Locorumnbsp;Compofitioni eos folummodo intentos fuifle inveni-mus,) dodtrinam exadlè compledleretur , atque id por-ro volumen in immenfum excrefceret , fi ad Loca,nbsp;qus funt lines curvs fecundi generis , uti nobis pro-pofitum eft, extenderetur; fed Arte Analytici per iE-quationum examen amp; prscepta generalia, quibusomneSnbsp;omnino cafus poftibiles refolvantur ac determinentur.nbsp;In quibus pertradfandis eum ordinem fumus obferva-turi, ut jam poft explicationem Elementorum Parabels , Hyperbols, amp; Ellipfis, ( fuppofiti notitii eorum »nbsp;qus ad linearum redlarum, angulorum, amp; figurarum re-dfilinearum,nec non Circulorum naturam pertinent) imnbsp;ventionem ac determinationem tradamiis eorum locorum , qus vel redls lines funt vel ex prsdidlis curvisnbsp;conftant; (lila autem amp;: nobis, ne quid temerè mute-

miiSj

-ocr page 257-

Lib. I. Cap. III.

camus.


mus, Locorum Tlanorum , SoMorumque tiomine ve-nient) atqiie eo ipfo oftendamus in primo curyarum ge-nere , pr^eter Circulum, non nifi Paraboiam , Hyper-bolam, amp; Ellipfin efTe recipiendas. Tradationiautem ulteriorum locorum, quas pertinent ad lineascurvas fe-cundi generis , fimiliter qiioque earundem curyarumnbsp;Elementa praemittenius. Cum verb ad ipfarum genera-tionem viam fternant non tantum defcriptiones Mnea-rum curyarum primi generis , hoc libro propofitae atquenbsp;explicatae, fed amp; multi alii iilas in piano defcribendi modi : operas pretium duximus eorundem modorum, quinbsp;certè infiniti funt, ut quilibet huic Ipeculationi inten-lus facile experietur , vel illos faltem hie adjungere,nbsp;quos aut ad defcriptiones curyarum fecundi generisnbsp;auxilio nobis fore, autMechanicae curyarum primi-gene-ris in piano delineationi praecedentibus aptiores judi-

Caput IV.

xyilia Tarabolam, Hyperbolam, ^ Elli^Jin in 2iano delineandi Methodus.

It triangulum quodcunque ifofceles A B C, amp; tarn aequalia

cruraAB, AC, quambafis BCutrinqueindefiniteprodu-

cum

tefta B K movcatiK in utramque partem, ita tamen ut crus A B femper applicatum maneat redlse DE, fimulque reda HI huenbsp;atque illuc promoveatredam CN, fibi ipfi Temper squidiftan-

f ^ X nbsp;nbsp;nbsp;tem;.

cantur, ut ad D, E, amp; F, G, nec non HI; fitque ab alterutro ^nguLorura ad bafin dudta qu2:vis redia termiaata, oppofito cru-rijEquidittans, utBK, amp;per terminumejufdem Kalteraredla,nbsp;utrinque indefinite extenfa, liberetranfeat, qus circa verticemnbsp;3nguli reliqui, nempepundlumA, utPoIum, circularitermo-bilis fit, veluti L A K M j ac denique redlse F G infiftens C N ipfinbsp;E parallela tranfeat per ipfarum F G amp; HI interfeftionemnbsp;C. Dico , fi angulus EBH atque ipfi ad verticem'DBl-----

ho R ir nbsp;nbsp;nbsp;TT/i.-^nu^nbsp;nbsp;nbsp;nbsp;iTir»nr*nbsp;nbsp;nbsp;nbsp;f

-ocr page 258-

E L E M. C U R V A R U M

tem, acrefiaBK adpolum Acirculariter moveri faclat pradi-*

dam L M , per pun-dum K femper tranf-euntem , interfedio-nem ipfarum C N, LM, qusE fit ad O ,nbsp;Parabolam defcribe-re,* cujus diameter eftnbsp;A D , parameter K B,nbsp;ac F G eandem con-tingens in verticeA.

In quacunqueenira ftatione conftitutusnbsp;fuerit angulus E B Hnbsp;feu D B I, fi interfë-dio redarum F G,nbsp;Hl defignetur per C,nbsp;atque ab interfedio-nis pundo O ad dia-metrum applicata fit OP ipfi F G tequidiftans: eritfemper KB

ad B A, hoc eft, ad A uti eadem A C ad CO*;nbsp;ac proinde * redangulumnbsp;fub KB , C O , id eft Snbsp;fub K B AP quadratonbsp;redaeAC, hoceft^,ipfiusnbsp;OP tequale.UndefiBA Cnbsp;angulus redus fuerit , eritnbsp;A D axis, fin minus, diameter , ad quam ordina-tim apj)licats faciunt an-gulosipfi BA C velBAGnbsp;angulo ^quales.

In tranfitu etiam hïc no-tandura eft , eodcm illo motu per interfedionem

ipfarum Hl, LM, puta Q^, Hyperbolam five op-pofitas

-ocr page 259-

Lib. I. Cap. IV.


pofitas Hyperbolas deferibi; utamp;, quamvis triangulum B A C ifofceles non foretnec ctiam refta B K ex angular! punóto B fednbsp;ubivis in refta A D eduóta eflet, niliilominus tatnen curvam A Onbsp;Parabolam fore; at verb nec parametrmn priori, neevertieem,nbsp;nec diainetrum poftcriori cafu eafdetn remanere, quas taincn illisnbsp;quoque cafibus determinare facillimum eft.

Quoniam autrem circa finem capicis pritni monuimus, curvam , juxta definitiones in principio ejufdem capitis propofitas, quMibet efficiente; amp; quocunque inter-•vallo deferiptam, fi angiili mobiles insequales fint ns quinbsp;ad direciricem funt ab eadem parte, Hyperbolam efiè,nbsp;idque Mechanicae ejufdem in piano delineationi non inutile judicamas : idcircoid demonftratione jam compro-bandum duximus, fimul oftenfuri, quo pa6lo eadem Me-thodus ad praediftas Hyperbolarum delineationes commode applicetuf.

Sit itaque efficiente I G, intervalto A L, amp; direElrice K L O, an-gulis autem IA L amp; K L A insequalibus, deferipta curva D A M ; dico eandem curvam Hyperbolam elfe; ac ft dudta a PoloKz^nbsp;dtredricem redta A K, ita ut angulus L A K angulo LAG squalls fit, centro A amp; intervallo A K circulus deferibatur, fecans ef- ^nbsp;ficientem in I amp; G , ad direclricem in K amp; Q^'', perque punfta I amp; eamkmnbsp;K, nec non per G amp; Q^ducantur redts IK, G. (^ftbimutub oc- in Knbsp;currentesin F, redas FI, FG Afymptotosefle'^.nbsp;nbsp;nbsp;nbsp;contin-^

* fi vero

niamigitursqualesfunt anguliAlK, AKIinterfe',

fimul fumpti angulo K A G, (qu.ppe tarn poftenor quam pno-re, - cum angulo IA K binos redos conftimunt); erunt quoque pundo-»„guU AIK fa. AIF amp; G At jU.po.c»ciualiumd.,nid,a in-ter fe squales, ac propterea reds I K F amp; A L parallels ; ^antve-ideoctue ficut IKF redxFGoccurnt,.itaamp;cvdem FGoccur- lutlamp;K Anbsp;nbsp;nbsp;nbsp;in 111)^,0

G Sc

in tv fis tangatibidemcirculumreaa.fUtlFinpriori, ScGFinpofterioricunicon-

•* 1,-^rnifur * per f prim. ^ per iz amp; ziprimi. 3 perzSprimi. ^ incalung. I lip. Siam uterque angulorL AIF amp; G AL redus eft,nbsp;nbsp;nbsp;nbsp;F, A B parallels erunt.

Sumpyo enimincurva purido utcunque, velutiD, applice-tur tarn angnlm mohiBs, Ut O A D , quam deferibens, ut O D, in fig,V.ex-ftatione utifuere, cumpereasdeferiptumeftpundumD.Qiio-bibito.

nec non

-ocr page 260-

« per X fexti, amp;

Elem. Curvarum rent defcribentes A L amp; O D, utpote ipfi IK F squidiftantes.nbsp;Sint itaque ipfarum occurfus in B amp; C, ac per B agatur re6tanbsp;B N diredrici K O asquidiftans, occurrensque defcribentiD Onbsp;in N: eritqueut GA ipfiAI, ita 'GBipü BFsequalis. Cum


autem ?n triangulis L A K, OQ^C sequales fintanguH adLamp;: 9 ’ ^nbsp;nbsp;nbsp;nbsp;quot; A L, C O parallelas,) fitque amp; angulus L A K

five G A L, id eft, GIF, aequalis angulo O Q^C, (quippe tam hie quam ille cum angulo K QG, vel KQJE duos reólos confti-

tuit


-ocr page 261-

2-53


tuit’,) ‘‘'aequiangula erunt eadem triangula LAKamp;O Q,C,,«i0.

five ^ N B C. Porro, llfig. per quoniatn anjrulus 5

AGEanguloIKoSAy'

ieu A L O ^qtialispÊTi5jEJn-eft, (quippe tain hic ^ * quam ille cum angu- ^ ^

d in cafu fig. 111 apparet, tarn angu-, lum O QJ quam LAK reftumnbsp;efTe, per i ? prirai, amp; j i tertii ; ac innbsp;fig. Vamp; VI angulosGI Famp; O QCnbsp;requales, per 3Z tertii amp; 21 ejufdem.nbsp;^ per i^primi,

lo I GQ_five IG F ^ ^ binos reélos confti-?^''

pr/mi amp;

•AGE

angulo

O A E iifdem five x-qualiDLis addito vel A LO ablato communi eftsequa-OAC’, compoCtinbsp;vel refidui L inbsp;Gad vel G A E £e- gulonbsp;quales quoquc funt.^^Q-ac E 0,A O fibi mu- aoTco^.nbsp;tuo occurrant; GE ftituit,nbsp;quoque amp; A D fibiPquot; ^9nbsp;mutuo occurrant ne- ^nbsp;cefTe eft 3 fit itaque;Xinnbsp;ipfarum occurfus E cafu fig.nbsp;punSumj amp; sequian- ^nbsp;gula erunt triangula, bae”'’nbsp;A G E, A L O, erit-quepropterea A L^per 4nbsp;ad AG, ucLOfive^^'f^’quot;nbsp;NBadGE. At veronbsp;G gnbsp;nbsp;nbsp;nbsp;(ob

12 tertii, in fig.111 ,per 15 primi amp; 51 tertii; in fi^.lV peri) primi, 18 £?quot; 31nbsp;tertii- in fgM per 15 primi O' 31 tertiinbsp;infig.Yl,per 13 primi ,quoniam angiilonbsp;I G Q__,equalis eji IK Qjgt;er 11 tertii.nbsp;tuit', ) atqueangulis rin fig.IInbsp;LAG, OAD


-ocr page 262-

Elem. Cvrvarvm

ptr [up. Jem,nbsp;^per^nbsp;fexti.

I per 11

quinti,

“i per 9 ^uinti,

Ï per fupgt; Jemonjir.

(ob triangula LAK amp; NBC ‘ fimilia ) eft quoque * eadera AL adAK, hoc eft, adeanderaAG, utNBadB C. unde pernbsp;confequenserit^, utNBadGE,itacademNBadB C. acpro-inde refftae G E amp; B C, ideoque amp; GBfcu*FB amp; CE, necnbsp;notiBE amp; F C aequales erunt. Denique cum,propter triangula

ffi

^pertq primi.nbsp;y per ^ ,

JiXÜ.

Sperfup.

demonflr.

ABE amp;DCE «fimilia, ^BE fit ad CE, hoc eft^ FC ad F B, ut B A ad C D: erit » recSangulum F C D fub extremis *-

quale redangulo F B A fub mediis. Quod cum Temper accida'^j

ubi-

^perisfextt.

-ocr page 263-

Lib. I. C A p. IV. nbsp;nbsp;nbsp;2,35

uticunque in curva aflumptum fuerit D pUndum , fequitur ' ' fet^ curvam DAM Hyperbolam efle , cujus Afymptoti FI, F G.nbsp;Quod crat oftendendum.

Exantedidismanifeftumeft, fi efficiens feu * contingcns , xit^pirs IG, ad Afymptotorum alterutram perpcndicularis fit, veluti innbsp;tertia amp; quarta figura, vel angulos mobiles L AI amp; L A G redosnbsp;fore, fi nempe intervalUsm, ut A L , aequidiftans dudum fit ei A-lymptoto cui efficiens ku contingcns IG ad angulos redos occur''


-ocr page 264-

Z^6 E L E M. C metris conjugatis H A, IG,nbsp;Hyperbola fit defcribenda, dii-dtis in calii pofteriore Afym-ptotis FI, FG, diametroIGnbsp;circulusdefcribatur, cjuifecetnbsp;utramque Afymptoton, puta

' Hf

___vtL ^

I;'|

«autal- in K dirQ^^dudiaqueperK amp;Q.

tan^Tt amp; OjCui dudta A L,Afym-alteram ptotorum aIterutri,utF Ijaequi-fccet, ut diftans, occurrat in L: facillimè inllfig. colligitur ex prsmiffis, finbsp;Ch acnbsp;nbsp;nbsp;nbsp;IG, intervallo A L, ac di-

Ili fig.in reiï/'/ce K O, curva dcfcribatur,

Gamp;K. eandem foreHyperbolam, quae delineanda proponitur.

Nonnunquamtarnen,utobliquoscircumferentiae amp; redari^ occiirfuseyitemus, haeceadem abfqueCirculi defcriptione enbsp;cere expediet.

-ocr page 265-

L I B I. C A P IV. nbsp;nbsp;nbsp;137

ItaquefijduftaAL Afymptotorumalterutri,utFI, parallela, ad eandem Afymptoton ducatur A K, ita ut L A K angulus angu-loLAG squalis fit, amp; per K reétaKO fecansprjediftam ALnbsp;iiiL, ita ut angulus FKO angulo F GI xqualisfit: eritxurva,nbsp;efficiente I G, intervallo A L, ac direSlrice K O defcripta, ca ipfanbsp;Hyperbola, qux qusritur.

Ad Mcdianicas porro Hyperbolarum defcriptiones non inutile forejudicavimus paucis liic oltendere, quonbsp;pafto vel angulis mobilibus redis, vel ita ut deferibens adnbsp;direBrkem fit perpendicularis, quaelibet Hyperbolic innbsp;plano dejineari queant.

Siitaque vel hoe,vel illo modo defcribenda fit in plano Hyperbola,cujus A/ymptoti fint F S,F T,quamque contingat reda S T, utrinque Afymptot* terminata: Duda ab alterutro pundorum S

vel T reda, veladhanc, veladil-lam Afymptoton perpendiculari,uti T V,quam ad F T angulos redos ef-ficere fupponimus , eidem TV pernbsp;pundum I ( nempe ita fumtum utnbsp;IF inter V F amp; S F media fit propor-tionalis)agatur sequidiftans I G,qusenbsp;continget quoque Hyperbolam 'nbsp;qusfitam ‘, propterea qubd fit V F gt; fw ^nbsp;ad I F, hoe eft % IF ad S F, uti ^ T Fnbsp;adG F.Ideoque defcripto fuper ean-dem I G circulo IK G, qui tangat ^ inbsp;Afymptoton F T in G , atquenbsp;nbsp;nbsp;nbsp;^

ram fecet in K, fi per K amp; G duea-tur reda K G O, cidemque occurrat qumii. diida ab A, pundo medio tangentis I G,reda A L in L, qux qui- pquot; Cor.nbsp;dem A L vel ad eandem IG, vel ad dudam K O fit perpendicula- ^ ^nbsp;ris : erit Hyperbola,quse efficiente IG, direElrke K O, atque inter-vatlo A L, ad eandem effictentem, diAimve direBricem perpendicu-lari,defcribitur, juxtaeaqusmodóexpofitafunt, hxc ipfa, qusenbsp;delineanda proponitur.

Similiter amp; vel datis quibufübet angulis mobilibus^ vel

Gg 3 nbsp;nbsp;nbsp;ita

-ocr page 266-

fa 1 amp; 11nbsp;Jèxti.

^ fa 14 fiaindi,


Vet


55


tertii.


^58 Elem. Cvrvarvm itaut deferibens ad ^^irÉ’^rifmdatosquoflibetanguIosnbsp;cfificiat quamcunque Hyperbolam in plano delinearenbsp;baud difficile erit.

CsEterum fequentem quoque Ellipfin in plano de-fcribendi rationem hïc adjeciflè fuum aliquando ufuni habebit,

Reda linea, ut A B C, ad Polum B circulariter mota binis fui pundis A amp; C, in eadem utcunque aflumptis ( five B fit inter Anbsp;amp; C, five C fit inter A amp; B, ) promoveat reftas A D E, D C F,

fibi ipfis Temper aequidi-ftantes, ac fe invicem ad redos angulos interfecan-tes : dico curvam , qua:nbsp;cöntijaua earundem inter-feéèione, veluti D, defcri-bitur, Ellipfin efl'e, cujusnbsp;centrum eft B amp; axesnbsp;G B H, IB K, nempc ma-gnitudine ipfarum A B,nbsp;B C duplae, pofitione verb ipfis A DE, DC F,nbsp;aequidiftantes per B Polum dublae, atque ibidemnbsp;bifariam divife.

Sumpto enim in eadem cur^a pnnélo utcunque,nbsp;veluti D, applicenturipfinbsp;defcribentes A D E,D C Fnbsp;inftatione utifuêre, cumnbsp;per illarum interfedio-nem defcriptum eft pun-öumD; noteturqueporrópundum ,ubi earumalterutra, velutinbsp;A D E, vel banc vel illam dudarum G H, IK, ex. gr., ipfamnbsp;G H, fecat, ut in L. amp; fit G A H circumferentia Circuli, qui pernbsp;motum punfti A defcribitur. Quoniam itaque eft ’ A B qua-dratum ad B C quadratum, hoe eft, G B quadratum ad B K qua-dratum, ut AL quadratum five * G L H redangulum ad LD

qua-




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2J9

Lib. L C a p, IV.

quadratum: conftat *, curvam G KH, uti prjedidum cft,.defcri- gt; /ie»- ij ptam Ellipfin efle, cujus axes funt G H , IK.nbsp;nbsp;nbsp;nbsp;hiijus.

Manifeftum autem eft , ft puncfta A amp; C squaliter a B Polo diftent, praedidam curvam Circuli circumferen-tiam fore.

agt;

Non fit deinde ABC una Hnea refla, fed angulus quicunque, fiveobtufus, fiveacutiiis ABC, fintque prsdidt* reda? DAE,



t) CF in pundds^ A amp; C ita jundlx, ut, cum carum altera uni ***nbsp;nbsp;nbsp;nbsp;cruri

-ocr page 268-

240 Elem. Cvrvarvm

cruri coincidat, (qucmadmoduminftationeAB CreédaDCF coincidit cruri B C ,) altera ad reliquum crus lit perpeadicularis,nbsp;(ficut in eadem ftatione recla D A E ad crus A B pcrpcndicularisnbsp;eft:) dicoiteruna, fiangulus ABC circaPolum B circulariternbsp;raotis puneftis A amp; C in utroquecrureutcunqueaflumptis promo veatredasD A E amp; D C F fibi ipfis Temper arqivdiftantes,cur-


vam, continuaipfaruminterfeflione, velutiD velK, defcriptam, Ellipfin efle, cujus femi-diametri magnitudine funtredx DB,nbsp;B G, nempe didorum crurum, ll opus tuerit, produdorum, por-tiones a perpendicularibus A D, C G, per affumpta punda A amp;nbsp;Creciprocèdudis, ad Polum interceptse; amp; quidem altera, utinbsp;D B, eciam pofitione; altera vero, ut BG, non item, fedBPipflnbsp;^qualis , redsqueD A E squidiftans.

gt; fx hy-poihc[l,amp; .

Si


Sic enim pratdidus ABC angulusin alia ftatione uteunque* ex. gr. , in HBI j ideoque prselata interfedio ad K. Demilftsnbsp;autem abl amp; Kadredam DF, ipfiusD Bduplam, perpendicu'nbsp;laribusIL,KM, notatisqueinterfedionem pundisad N amp; O,nbsp;quoniam a:quales live iidem funt angulus ABC live O B L amp;nbsp;per 19 F1BI, eriint quoque, addito vel ablato communi H B F, anguUnbsp;primi. H B O amp; I B L squalcs; ideoque triangula HBOamp;IBL, obnbsp;angulos preetereaad O amp; L redos sequiangula. Suntautem^*

-ocr page 269-

Lib. I. Cap. IV. nbsp;nbsp;nbsp;^4I

amp; aequiangula triangula C B G amp; M N K, cum tarn hoc quam il-lud triangulo OBN nbsp;nbsp;nbsp;quarecumfit ^D Bquadratum '

ad N B quadratum, ut A B quadratum, id eft ^, H B quadratumj^^o^*^ ad O B quadratum, erit per converfionem rationis D B quadra- M rekos,nbsp;turn ad D NF re(ftangulum,ficutHB quadratum adHO^ qua-dratum,id eft^, miBI quadratum ad ILquadratum, utiB Cnbsp;nbsp;nbsp;nbsp;.

quadratum ad K M quadratum id eft utiB G five B P quadra- viadvey-tum ad KN quadratum, amp; permutando D B quadratum ad

^ per 4

3 exhypothefi. 4 per Cor. ji) quinti. 1 per ^fectindi. ^ per ip] prim. 7 per a. Cr 2.1 fixti. 8 cequalis cfl-enim B C fp(i BI, €3“ IL K M. 9 per A, pxti, propter trianouUnbsp;CBG O' MKN aquiangula. ^°pcri6qumti.

B P quadratum, ut D N F relt;5l:angulum ad K N quadratum. Ac proinde Ellipfis eft curvaD K P F,ititerfelt;9:ione uti prtediöum eftnbsp;defcripta “ , cujusfemi-diametriconjugata^D B,BP; ideoque quot;perilnbsp;B centrum, ac D A E contingens Ellipfin in vertice D

Notandum Wc eft, quodfireftusforet A B C angu lus, interfecftione, utiprsediftumeft, noncumm,nbsp;nbsp;nbsp;nbsp;'

reftam lineam defcribi. nbsp;nbsp;nbsp;^

Quemadmodum autem Ellipfin , quae fiiperi^s per niotum pun(fti in una eademque refta defcripta fuic,nbsp;nunc per duarum redarum interfeftionem delineavi-Pan Ihnbsp;nbsp;nbsp;nbsp;Hhnbsp;nbsp;nbsp;nbsp;mus,


-ocr page 270-

^4^ Elem. Cvrvar. Lib, I. Cap. IV. mus, ica amp; Parabola Hyperbolaque , quarum genera-tiones folummodo per limiles interfeftiones in prsce-dentibus expolliimus , per motum punfti in una eadem-que refta del'cribi pofTunt. At vero quoniam praedirfarumnbsp;curvarum generationes , ut jam ante quoque monui-miis, infinitae funt, atque earum facillimas quidem acnbsp;maxime naturales a nobis jam propofitas exiflima-miis, hifce dintius inhaerendum non videtur; itaquenbsp;ad Locorum ‘Planorum, Solidorumque inventiones acnbsp;determinationes progredimur.

I 0-»

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=4?

iOHANNIS DE

WITT

E L E M E N

T A

C V R V A

R V

M

LI B E R SECVND VS.

L I N E A R V M.

C A P V T I.

PROPOS ITIO GENERALIS.

' N omni quseftione , ubi indagandus i proponitur Locus , five is fit ad li-neam redlam/ive ad curvam, fuppofi-tis duabus lineis re(5i:is incognitis at-que indeterminatis, datum vel affum-Iptum angulum comprehendentibus,nbsp;tanquam cognitis ac determinatis,nbsp;devenitur ad Aquationem» affumptum quodlibet qujefitinbsp;Loci puiiftum determinantem; in qua quidem squatio-ne, poftquam ad fimpliciifimos terminos erit redudla, finbsp;neutra incognitarum ad duas plurefve dimenfiones affur-gat, hoc eft, fi iieque in fe, neque in alteram incognitamnbsp;dufta feu multiplicata reperiatur, qu^fitus Locus eritnbsp;linearefta: At fi eariindem incognitarum altera adqua-dratumafcendat, altera veto non item, fed neque infe,nbsp;neque in alteram incognitam dufta fit, erit Locus quae-fitus Parabola. Quod fi vero utraque ad quadrarumnbsp;afcendat, five altera in alteram duifta in squatione reperiatur (altius enim aequatio non alfurget, ft de loconbsp;Plano Solidove quaeftio fit) : erit Locus quaefitus velnbsp;Hyperbola , vel Ellipfts , vel Circuli circumfercntia.

H h X nbsp;nbsp;nbsp;Quo-


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2-44 Elem. Cvrvarvm Quorum quidem omnium particularis determinatio,nbsp;defcriptio , Sc demonftratio variis módis fieri poteft;nbsp;at verb ex fimpliciffimis , generaliffimisque aliquemnbsp;annotafiè fufiècerit.

Ac primo quidem cafii , cüm neutra quantitatum incognitarumadduasplurefve dimenfiones afcendit, finbsp;earum unaexprimaturper x, atque altera perjy, poteftnbsp;^quatio ad aliquam fequentium formularum reduci.

I. nbsp;nbsp;nbsp;y zo ,five(pofitoazo b)y zo x.

II. nbsp;nbsp;nbsp;JV 00nbsp;nbsp;nbsp;nbsp;five, pofito,utfupra ,yzox c.

IILjV03 , fivejy od xc.

hx

IV.JVOO—^ c, {vicy zox c.

Fiat autem earundem quantitatum incognitarumfe-ciindüm regulam talis afiiimptio , ut initium unius, verbi gratia, ipfius x, certum fit amp; immutabile, utquenbsp;eadem illa quantitas ex certo amp; immutabili illo initionbsp;in linea reifta pofitione data intelligatur indefinitè extendi , altera verb indeterminats quoque longitudinisnbsp;liiiea priori in extremitate incerta in dato vel aflum-pto angulo conjutigi. Quibus quidem fuppofitis, ea,nbsp;qu£e prxdicfta funt , fequentibus Theorematis non in-congriiè proponi, determinari, ac dèmonftrari pollènbsp;videntur.

Theorema I.

Tro^ojïtio I,

h X

Si aequatio fitjy zo - , erit locus quaefitus linea reéla.

Sit enim ipfius x initium immutabile punólum A, atquc eadcn» illa X perreftam AB indefinitè fcextendere intelligatur. Dein,nbsp;fumpto in eadem A B pundtq utcunque, veluti B, agatur B C in

angulo

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Lib. II. Cap. I. nbsp;nbsp;nbsp;a45'

angulo A B C, ipfi Hato vel affumpto aequali j ita iit eadem fit ratio intercepts ABadduiSlamB C, quseftcognitsad b cognitam.

hoc eft, ut fit mi 4 ad ita A B ad B C. Deni-que per puncfta A amp;.Cnbsp;ex' /nbsp;nbsp;nbsp;nbsp;ducaturredaACjinde-

finitè extenfa , eritque hsc ipfa locus qusfitus.

Etenim affumpto in A C pun6to utcunque,nbsp;veluti D , duftaque D Enbsp;in angulo D E A, datonbsp;vel affumpto squali, fi eadem DE 'focetur^, erit ‘ ut A B ad '

Be , hoc eft, ut4ad^, itaAEadED, hoceft, ita .v ad^. Et^’'|quot;quot;^ ^

fit ^ CO bxy hoc eft, dividendo utrinqueper^, erit^ co nbsp;nbsp;nbsp;i6

Qiiare cum punSum D utcunque fumptum fitinlinea A C, erit eadem de omnibus aliis lines A C pundisdemonftratio, acnbsp;proindeipfa A Clpcus eft qusfitus. Atque ita non folum Theo-rematis propofiti veritas demonftrata, fed amp; Locus qusfitus de-terminams eft.

Theorema II.

^rofojitto i.

Si ^quatiofit^ 00^’quot; ^'. erit Locus quxfitus linea

ré^a.

Pofitis, faöisque, ut fu-pra, agatur infuper ex A re-da A F ipfi B C parallela, atque ad eafdem cum ea partes, qusfitsqualis ccogni-ts. Et ex F duda F G parallels A C, dico candem F Gnbsp;effe Locum qusfitum.

Sumpto enim in F G pun-do utcunque , veluti G, du-d%ue GE in angulo AEG,

Hh 5 nbsp;nbsp;nbsp;dato


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Elem. Cvr.varvm

dato vel aflumpto squall, qas fecet reólam AC in D, (leadem t per 19 G E voceturƒ, erit E D OD / — c. Atveröeft,utfupra', utiABnbsp;primi,Cr adBC, ita A E adE D jhoceft ,uti«ad^,itaA-ad/ — c: acpro-t^pcriónbsp;nbsp;nbsp;nbsp;* lt;«7—^.Vjvel^^X hx ac, adeoque,fa(3:adivi-

fione per a,_^ nbsp;nbsp;nbsp; c- Quod denaonftrandum determinan-

dumque erat.

Theorema III.

^ropofitio 3.

Si aequatio fit jy x 7! — , erit Locus quaefitus linea re6la.

py nbsp;nbsp;nbsp;Pofitis faöisque ut in

Theoremate iquot;quot;®, agatur infuper ex A rcd:a AF,nbsp;/ ipii B C parallela , atquenbsp;ad oppofuas cum ea par-‘tes, qus lit squalis cco-gnits. Et ex F duöaite-rum F G ipli A C paralle-

TéiX____ la, fecanteredam AB in

B E nbsp;nbsp;nbsp;H, dico HG elleLocum

quslitum.

Sumpco enim in eadem ,nbsp;nbsp;nbsp;nbsp;pundlo utcunque veluti

G, duftaque G E in an-guloAEG, dato vel alTumptosquali, qusproduélafecet A C iperilt;) inD, fi eadem G E voceturj, eritE D x lt;« c. lam veto eft’nbsp;ex conftrudione, ut A B ad B C , ita A E adE D, hoe eft, utadnbsp;4pa'16 itS'-vad^ c: acpropterea ^ay aezobA:,velajzobxac^

adeoqiie, fada divifioneper lt;?, / X nbsp;nbsp;nbsp;— c. Quod eft propofi-

tun..

T HBO'

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147

Lib. II. Cap.

Theorema IV.

Tro^ojitio 4.

Si aequatio fit jy x c—erit Locus quaefitus linca

rcdla.


Pofitis, faciisque, ut in Theorematenbsp;quod

excepto

pun(3:um C ab op-pofita parte ipfius AB cadat , quodque an-gulus ABC tequa-lis fit dati vel aflum-pti anguli ad binosnbsp;redos complemen-to, quemadmodum innbsp;adjunda figuraappa-ret , agatur ex F re-ftaFGjpfi AC pa-rallela, occurrcns reds A B in H : diconbsp;FH effe Locum quse-fitum.

Sump to enim in FH pundoutcunque, velutiG, dudaque CE inangulo AEG, dato vel aflumpto squali, quajprodudanbsp;fecet A C inD, fi eademGE voceturj, eritE D x c—y. Cum-qiiefit ‘ ex conftrudione, ut ABadB C, ita AE adE D, hoc ’ peri^nbsp;utlt;iad^, itasad c—7; eritpropterea^^ic — ayZDhx, vcl ^ ^9

— ^.v,ideft,divideiidoutrinqueperrf!,703c--. Quod 4 fixti.

„ nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;**nbsp;nbsp;nbsp;nbsp;^ per 16

cratpropofitum. nbsp;nbsp;nbsp;Jhti.

At verb fieri etiani poteft , ut per operationem, priufquam ad jequationem deveniatur , quaiititatumnbsp;incognitarum altera penitus evanefcat , alteraque folanbsp;^licui cognitse quantitati aequalis remaneat ; atque

exiii-


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2,48 nbsp;nbsp;nbsp;El EM. CVRVARVMnbsp;nbsp;nbsp;nbsp;^

exinde bins infuper formuls nafcuntur , qus hue re-ferri debent: nimiruni,

I. jy DD , vel X. X 00 c.

Theorema V.

Tropofitio 5”.

Si squatio fitjy 00 c, Locus qusfitus eft linea redla.

T'.

/

/

Sit quantitatis a-, qu3e per operationem evanuit,nbsp;initiutn immutabile punquot;nbsp;dum A, atque eadem ilia X per redam A B in-

__ definite fe extendere in-

telligatur. Deinde ex A duda AF 00 c, facientenbsp;cum AB angulum, ipfi dato vel afliimpto autejufdem adbinosnbsp;red:osfiipplementosquaIem, fiexFagauir F G ipfi A Bparalle-la, dico eandem F G efle Locum qusefitum.

Etenim aflumpto inF G pundo utcunque, veluti G, dudaque G B ipfi A F parallela, apparet eandem G B omnesque ipfi £equi-* J?quot; 34 diftantes i' reds A F fore squales, hoc eft, efle t oo c. Quod eratnbsp;demonftrandum.nbsp;nbsp;nbsp;nbsp;gt;nbsp;nbsp;nbsp;nbsp;7

VI.

Theorema

Tropojitio 6.

Si squatio (vcxzoc, erit Locus qusfitus linea re^la.

I nbsp;nbsp;nbsp;In linea A B, qus, ut fupra,

proA; concepta fit, fumatuta pundo A longitudoA B squa-lis c cognits,atque ex B in datonbsp;vel aflumpto angulo ducatucnbsp;reda BC. dico eandem B C»

indefinite produdam, efle Locum qusfitum.

do

__Su mp to enim in eadem pun'*


-ocr page 277-

Lib II. C A p II, nbsp;nbsp;nbsp;2,4p

öo utcunque, velutiC, erit ex hypothefi CB cum priore AB lt;omprehendens angulum A B C dato Velaffumptoaequalemjpo-teritque proinde cadem C B vocari At veto eft ex conftrudio-ne, amp; remanet Temper A B, hoc eft, .v CO c~ Quod eftpropofitura.

C A P V T II.

p Orro fccundo cafu, fupra exprellb, cum iiempc in aequatione , ad fimpliciffimos terminos reduft^,nbsp;quantitatum incognitarum altera ad quadratum alcen-dit, altera vero non item , fcdneque infe, neque in alteram quantitatem incognitam dufta reperitur: :potericnbsp;tequatio ad aliquam fequentium formularum reduci.

I. nbsp;nbsp;nbsp;jvjy CO ax 'Inbsp;nbsp;nbsp;nbsp;(ayoDXX

II. nbsp;nbsp;nbsp;yyX) ax bb\ , r \ay bbzoxx

ni /y 00 nbsp;nbsp;nbsp;ay-^bboDxx

IV. 00ax- -bbj nbsp;nbsp;nbsp;\bbajyzDXx.

Supponendo amp; x effe quantitates incognitas, velab initio conceptas, vel poftmodum afl'umptas, ut mox latius explicabitur.

Theorema VII.

^ropojitio 7.

Sia;quatiofitjyy CO ax, velconverfim ayo^ xx: erit Locus qutefitus Parabola.

Sit ipfius A- initium immutabile puruSum A, atquc eadem ilia a* perreflam AB indefinite fe extendere intelligatur, amp;fitdatus

vel afliimptus angulus ae-qualis angulo ABC; Af-1'umatur primo cadem A B ut Parabola; diameter , adnbsp;quam ordinatim applica-tx faciant cum ipfa angu-los sequales dato vel af-fumpto angulo A B C, cu-:}usque lams rcdum A Fnbsp;Pare //.nbsp;nbsp;nbsp;nbsp;1»


-ocr page 278-

« per 10 Coroll,nbsp;primii amp;nbsp;4 Coroll,nbsp;fecundinbsp;hujus.

xyo Elem. Cvrvarvm fit aequalc «cognitx. Dico Parabolam ADC, quie 'perpra?*nbsp;didasdiametri verticem A defcripta fit, habeatque latusreturnnbsp;eidem diametro correfpondens 00 lt;*, efle Locum qiisefitum.

Sitenim ineadem curva ADC aflumptum pundumutcun-que,veIutiD, dudaqueD E inangulo AE D dato velaflumpto jequali, fiipfaDE vocetiir/jcrit, exnatura Paraboles^ quadra-tumexEDooFAE rcdangulo , hoc eft, j; oo ^ a:. . Quod eratnbsp;propofitum.

Ad demonftrationem autem fe-cundae hujus Theorematis partis iifdem utfupra fuppofitis,ducendanbsp;eft ex A pundo reda A H ipfi B Cnbsp;parallela, atque eadem A H afl'u-menda pro diametro, ad quam or-dinatim applicatie faciant angulos,nbsp;dato vel aflumpto angulo ABCnbsp;feu A H C aequales, ac cxtera, utnbsp;fupra , eritque Parabola ADCnbsp;Locus quasfitus.

Eft cnim ^ quadratum ex G D five AE quadratum aequale re-dangulo fub F A 6c A G, feu F Anbsp;amp; E D,id eft,AT x OO dj. Quod eratnbsp;demonftrandum.

REM A VIII.

^ropojitio 8.

Si aequario ^\x.yy zo ax-^-bh aut converfim ay-\-bb ZD XX, erit Locusquaefituslinea Parabolica.

Sit ipfius X initium immutabile A pundum, atque eadem ilquot; la X per redam AB indefinite feextendere intelligatur, fitqaenbsp;angulusdatusvel aflTumptussqualisangulo ABC. DeindepfO'

ducatur A B versus A ufque ad G,ita ut fit A G oo ~ ; aflumpto'

que G B pro diametro, adquamordinatim applicatae faciant an' culos sequales dato vel aflumpto angulo ABC, cujusquelatu*

redum


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Lib. II. Cap. II. nbsp;nbsp;nbsp;2.5'!

G F fit jequale 4 cognitat: dico Parabolam G C D, quas

per prsediösE diame-tri verticem G dc-feripta fit , habcat-que latus redum ci-dem diametro cor-refpondens CD 4 , efle Locum quxfitum.

Sumpto enim in eadem curva punftonbsp;utcunque, velutiD,nbsp;dudl^ue DE inan-gulo A E D, dato vel

afiumpto jcquali, fi ipfa D E vocetur ƒ, quoniam G E five A E

A. G eft X — j atque ex natura Paraboles * quadratum ex' P^gt;' i a ^nbsp;nbsp;nbsp;nbsp;*nbsp;nbsp;nbsp;nbsp;primi hn-^

m.


E D X reöangulo fub F G amp; G E, eritj^ ZO ax bb. Qiiodgt; primo erat demonftrandum.

Ad explicationcm verb fecunda: hujus Theorematis partis iif-demutfuprapofitis, diicatur ex Areöa AH ipfi B C parallela;

eademque produda versus A ufque ad G,ita ut A G fitx ^, di-


fi ad G H diametrum latere redo G F X 4 Parabola deferiba-*ur ut G C, qu2E fecet redam A B in I, curvam ID efle Locum S^ïfitum.nbsp;nbsp;nbsp;nbsp;2 per r

Eft enim ® ex natura Paraboles redangulum fub FG amp; GHprimih»-

li 2 nbsp;nbsp;nbsp;con-^'“’


-ocr page 280-

El EM. CVRVARVM contentum sequale quadrato ex H D feu A E, ac proindc, quoquot;nbsp;niam G H, five D E A G, 00/ ^^, atquc F G aD(«,erit,falt;5i:anbsp;debita mulciplicatione,nbsp;nbsp;nbsp;nbsp;^ ^ CD a; ar. Quod cft propoficum.

Theorema IX.

Tropofipio 9.

Si ffiquatio (\tyyzo a x — h h aut converfim ay — b b o:gt; XX, eritLocusquaefttuslineaParabolica.

Suppofitisiifdem, quseinprïecedentiTheoremate, auferator abA BredaAGcX) fiantque castéra, ut ibidem didtum eft.;nbsp;dico curvam G C D efle Locum quaefitum.


j, nbsp;nbsp;nbsp;~nbsp;nbsp;nbsp;nbsp;* -

frimihu- Paraboles ‘ quadratum ex E D feu squale redangulo fub

Sumpto enim in ea pundio utcunque, veluti D , dcmifsaqUÊ DE ipfi CB parallela, fieadem DE vocetur^, erit ex natura

hh

E G amp; G E, id eft, produdlo ex «i in ar--, nimirum, ax

Qixod demonftrandum determinandumque erat.

Ad cxplicationem autein fecundse hujus Theorematis partis, iifdtmut fupra pofitis, ducatur ex A redia A H ipfiB C parallels,

atqueab eafubdudia A G CD fiimatur G H pro diametro, amp;c.

atfupra, dico curyatn GGD fore Locum qujefitum.

-ocr page 281-

C A P. II.

H/

A. nbsp;nbsp;nbsp;BE

Eftenim ' cxnaturaParaboIes reflangulumfub Contcntuma:qüalequadratoex HDfeu AE, ideoque, quoniam

G H fiveD E ^— A G squatur^ — ^ j atque F G QO ^,erit,faöa debita multiplicatione, ay.— hlgt;o:gt; xx, Quod erat propofituna.

Theorema X.

Tr opfit io 10.

Si aequatio Cxt yy nbsp;nbsp;nbsp;h ba x aut converfim b b —ay

00 X X , erit Locus quaefituslineaParaboIica.

Sitenitn, utfupra, ipfius x initiiim imraiUabile Apunöam,

eadem x in re-fta A B indefinite fe ab'A extendere versus B ; angu-lus veró da-tus vel aflfcim-ptus efto £E-qualis angulonbsp;bhnbsp;nbsp;nbsp;nbsp;^

Abc. Deinde ab AversmBaffampta AGX fumaturG A

li 3 nbsp;nbsp;nbsp;progt;

intelligaturque

-ocr page 282-

^5’4 Elem. Cvrvarvm

pro diametro , ad quam ordinatim applicatse faciant angulps a’quales dato vel aflumpto ABC, aut ejufdem ad duos rediosnbsp;fupplemento. Quo fado, fi per prïEdidae diametri verticem Gnbsp;versus A Parabola defcribatur , cujus latus redum G F ei-dem diametro corrcfpondens fitGOlt;«j quseque Parabola redatnnbsp;AI ipd B C parallelam fecetin I: dicoejuldem Parabolte por-tionem, inter verticem G amp; pundum interfedionis I interce-ptam, nempe curvam G CI, efle Locum qutefitum.

per I

primi

hujus.

Sumpto enim in ea pundo utcunque, veluti D, demifsaque D E ipfi C B parallela, fi eadem D E voceturj , cum ‘ ex nam-ra Paraboles quadratum ipfius D E fit aequale redangulo fub F G

amp;GE,amp;GEfiveAG — AEfit GO —^•—-v, acF GGOlt;«,fada

debitamultiplicatione,erit^ƒ Z£gt; hbnix. Quod demonftraa dum deterrainandumque erat.

H

* per ean-dcm.

..:x

D

\

\

C

»¦

\

B

Ad explicationem au-tem fecund^ hujus Theo-rematis partis, iifdem ut fuprapofitis, ex Aduca-tur A G ipfi B C parallela

atque GO ^^jaflumaturque

GA pro diametro , amp;c. per omnia, ut fupra, exce-pto quod pundlura interfedionis I fit in reda A E.

bh

Cum enim duda D H ipfi A B parallela ^ ex na-tura Paraboles redangU-lum fub F G amp; G H con-tcntum fit tequale quadra^nbsp;to ex H D feu A E, fitque

GH five AG—^EDgd ~ nbsp;nbsp;nbsp;atque FG go lt;*,fada multipli

catione, ut decet, erit^^—ajcoxx. Quod erat propofitum.

Reguldb

-ocr page 283-

L I B. 11. C A p, IL Regula unï'verfalis , modt^fque redmendinbsp;omnes aquatioyies^qua e% con-venienti ofe-ratione froducuntur, cum Locus quafitusnbsp;ejt Parabola , ad aUquem quatuor ca-Juumj jgt;racedentibus totidemTheorema-’nbsp;tïbusjam exfUcatorum.

Si contingatut quantitas incognita , quae in sequationc ad duas dimenfiones afcendit, in eadem quoque invenia-turunius dimenfionis,eum alia,five cognita, five incognita quantitate , vel etiam cum utraque planum aliquod fa-ciens, locoejufdem alTumenda eft alia, vel ipfam exce-dens, velab ea deficiens dimidio quantitatis, quacum ilianbsp;planum, uti diftum eft, conftituere reperitur, pro diverfanbsp;didli planifgno Hh vel —afteftione. Quo opere ipfa ae-quatio ad aliquem quatuor prascedentium cafuum redu-cerur, ita ut ei convenientem lineam Parabolicam determinate, per ea quae fuperiusfuntexplicata, baud difficile fit.

Exem^la reduBtonis aquationum ad formulam Theorematis VII.

Si acquado -{-zayCDb x—^-aa-, afTumpto, juxta Regu-Istn, nbsp;nbsp;nbsp;ZDy- Hincliubique insquadoneloco

jpfius^fubftituatur2: — a, ejufdemquequadratumloco yy: ha-bebitur?:?:— z nbsp;nbsp;nbsp; zaz.zaa^bxaa^ hoc eft,

otniffis iis quse fefe mutuo tollunt, erit?.?,GO h x. Vndeftadm spparet aequationetn eflè redudam ad formulam Theorema-bsVlI, acproindeLocum quxfitumefle Parabolam. Adcujusnbsp;Ipecificam determinationem efto inappofita figura ipfius:vini-tiumimmutabile A puntSum, eademque .v intclligatur fc ab Anbsp;perreólam AE indefinite extendere; fitqucdatus vel affumptusnbsp;^gulus, quern ƒ amp; a; comprehendunt, xqualis angulo EAF.nbsp;Peinde, quoniam eft cd 7 ^, fi 7 fupta lineam A E exfurgerenbsp;ïhtelligatur, ducenda eft infra eamrecfta GB ipfi A E parallela,

ka


-ocr page 284-

Elem. Cvrvarvm

ita ut pars reftx AF, oraaiumque ipfi parallelarum, intercepta

inter A E amp; G B, ve-luti A G, aequetur lt;1 2 Tgt;y^nbsp;nbsp;nbsp;nbsp;cognitse. Porrö pr^-2

dióta G B afl'umenda eft ut Parabolae diameter, adquamfipe2^nbsp;ejufdem verticem G2,nbsp;exiftente G F laterenbsp;refto, ipli diametro

1

G B correfpondente,

2

CO Parabola defcri-batur , fecans reétam A E in I : dico cur-vam I D indefinitenbsp;versus D produdafflnbsp;cfle Locum quajfitum.

^ nbsp;nbsp;nbsp;Etenim afi'umpto in

F2 nbsp;nbsp;nbsp;eadem curva punfto

utcunque, veluti D, duclaqueDEipfi A F parallels, fi eadem DEvocetur^, produ-caturque donee praediöae diametro G B occurrat in B: erit esnbsp;conftruöione interceptaE B co lt;«,acproinde totaD B 00j'4-.(2gt;nbsp;hoe eft, z- Quarecum exnatura Paraboles quadratumex DBnbsp;aequetur reótangulo fub F G amp; G B, vel F G amp; A E: erit quoquenbsp;zzZO ^v.five, reftitutoj-H^locos;, 2aj aaCOnbsp;eftjj^ 4-2 CO ^ V—aa. Quod demonftrandum determinan-dumque erat.

Quód 11 aequatio fuiflet — z ay^bx-aa, fafla aflum-ptione lècundüm-Regulam, atque operatione, ut fiipra; deven-tum fuiflèt ad eandem jequationem, nimirum,c zCO bx. Sed quo-niam z eo cafu juxta Regulam aflumenda fuiflèt coya, idcirco quoque diameter G B (iifdem ut fupra pofitis ) non infra , fedfuquot;nbsp;pra redtam AE cecidiflet, cseteraque omnia eodem quo fupranbsp;modo expedienda fuiflènt.

Siverójequatiofit byaa'^xx-^ z 4 v,qus eft converfa fu-periusexpofitce, alTumpto juxta Regulam v^qx-^-a ,erit •'2

COv. Quare filoco ipfius x inaequatione fubftituatur 2/—lt;lt;,atque

-ocr page 285-

Lib. H. Cap. II. nbsp;nbsp;nbsp;^^7

hujus quadratum loco xx'. erit hyaaZD vv—iav aa^ — 2 44, hoc eft, oraiffisiis, qusfetnutuo tollunt, erftnbsp;hy ZD vv.

Vndeftatimapparet, redudamefle aequationcm ad formulam prxdtdi Theorematis feptimi converfim , ac proinde Locumnbsp;quïfttum effe Parabolam. Ad cujus fpecificam determinationemnbsp;efto in appofita figuraipfms x initiumimmutabik punöum A,

intelligaturque eadem x a prasdiflo punöo A per retftam A E indefinite fe extendere, fitquedatusvel affumptusangulus, quern comprehenduiit7 amp; x, tequalis angulo A G H velF G H. Deinde,quoniam v sequatur x 4, producenda eft redta A E versus Anbsp;ufque ad G , ita ut A G fit 00 j amp; ex G ducenda eft G H, faciensnbsp;^trgulum E G H vel F G H dato vel aftumpto angulo asqualem,nbsp;ipkque G H ftimenda eft pro Parabol* diametro, ad quam fi pernbsp;ejus verticemG atque latere redoF G zob Parabola defcribatur,nbsp;ut G D: dico curvam G D effe Locum qusefitum.

Sumpto enim in ea pundo utcunque, velutiD, dudaqueDE

ipfi H G parallela, fi eadem D E vocetur; , cum G E fit OO x 4 feu tvjatque ex natura Paraboles F G H redangulum oo quadratonbsp;lt;ïxFlDfivcGE,erit^jOO't/'t', five,reftitutox-|-4loco2/, hynbsp;CDxx 24x-F44,feu^7 —lt;?lt;«OOxx-F2,4x. Quoddetermi-^andum, demonftrandumque erat.

Quod fi jequatio fiiiffet by—4 aZDxx—2 4 x,eadem per omnia mutatis mutandis fecundum Regulam inftituenda fiiiffet opera-tio, cecidiffctque eo cafu pundum G inter A amp; E.

quot;Part II. nbsp;nbsp;nbsp;Kknbsp;nbsp;nbsp;nbsp;Eodem


-ocr page 286-

Elem. Cvrvarvm

1 b xy


EodemmodofisequatiofitjjH- -—-^icyzobx:


lbo


-cc^


hx

aflumpto juxta Regulama, Xj 7 ^‘ nbsp;nbsp;nbsp;30

Quofubftitutoinlocumipfius^, ejufdemquc quadrato loco/j, expunftisque iis, qu* fe invicem tollunt, atque omnibus rite ordinatis fequentem formam induta erit fuperior aiquatio:

Z.Z.ZD x b X, auts.?: CD jf.fi loco i^ ^fubftituaturlt;/.

Vnde iteriim apparet, squationem efle reduftam ad formulatn Theorematis VII, ac proptereaLocum qujEfitum efleParabo-lam. Ad cujusfpecificamdeterminationem efto in fequenti figu-ra ipfius x initium immutabile pundum A, atque eadem x ab Anbsp;pundo per rcdam A E indefinite fe extendere inielligatur, fitquenbsp;datus vel aflTumptus angulus, quem^ amp; vcomprehendunt,sequa-

lis anguloE AFvelE AG. Deindequoniams:efl:OD/- -c-f-

AA*.

/E

/B

fi y fupra lineam A E exïurgere in-telligatur, velutinbsp;E D,ducendapriquot;quot;nbsp;mum eft infranbsp;eandem reda G Bnbsp;ipfi parallela, itanbsp;ut partes redsenbsp;F G omniumquenbsp;ipfi aqüidiftan-tium inter praedi-das AE amp; GBnbsp;intercepts;, velutinbsp;AGjEBjSquenquot;nbsp;tur £¦ cognitse. Quoperad», cum qujevis reda, qus poffit effe/jnbsp;ad redam GB produda, ut, exempli gratia, DB ,fitCD^

oportet ipfi adhuc adjungere ut fiat a;qualis aflumpto.

Quare, cum G B feu A E indefinite fumpta fit CD v, fi ex G juxta I Theorema hujus libri infra eandem G B reda ducatur , ut G C;nbsp;ita ut omnium ipfi G F parallelarum partes inter G B amp; G C in-sercepts, veluti B C, ad partes ipfius G B inter G amp; didas pa-

rallelas

-ocr page 287-

Lib. II. Cap. II, nbsp;nbsp;nbsp;^59

nllelasinterceptas, velutiBG, eandetnrationemhabeant,qU£E eft inter bamp;ia. Quod ipfum ut fiat, ftatuatiir ut a ad b, ita G B ad

B C; eritque B C CO • Eodem modo reclse omnes ipfi B C pa-

hx

rallelse, qu^ a G B ad G C ducf.ntur, erunt OO - . Atque ita re-

öaquïlibetfupra AE exfurgens, quxpoffitefl'epoftquamad reeftam G C erit produefta, ut, exempli gratia, D C , erit coj e

^ feus:. Hujusigiturquadratumcumdebeatefleco^;^a;,fta-

timindeapparet, fi Parabola deferipta foret ad diametrum G C, cujus latus redum GF ita efl'et aflumptum, utredangula, fubnbsp;eodem latere redo amp; diametriportionibus, inter verticem amp; or-dinatim applicatas interceptis, contenta, forent codx, eandemnbsp;illam Parabolam fore Locum qusefitum. At verb cum ratiore-Bad redam BC, aliarumque fimilium, cognitafit, nem-pCjUt^ad ^jlrtqueltidemnotus angulusGB C,fub iifdem com-prehenfus, utpote aequalis dato vel aflumpto E A F: erit pro-pterea quoque * nota ratio.GB ad GC, aliarumque fimilium,nbsp;quae fit ut a cognitx ad e cognitam. Hinc cum G B feu A E inde- fextUnbsp;finite fumpta exprimaturperx,erit G C itidem indefinite fiimpta,nbsp;hoc eft, omnis diametri portio inter verticem amp; ordinatimap-

plicatas intercepta co ^ • Qpse cum in latus redum duda pro-duceredebcat squationis terminum dx, idemquoquetequatio-terminus per - divifus ut prsedidum latus redum refti-tuat necefle eft: aeproinde per eandem divifionem cognofeitur qusefitum latus redum squari- . Sumpta ergo GF co pro

iatereredo, fi ad diametrum GC, ut fupra didum eft, deferi-BaturParabolaGID, fecansredamAE ini: dicocurvamID fore Locum qusfitum.

Atque hie, Ut amp; in aliis fimilibus exemplis obiter hotaiidum, fi Parabola deferipta prjtdiftam A E nonnbsp;fecaret, id certo indicio fore, qusftionem propolitam,nbsp;per quam legitima operatione ad fupra exprelTam se-^uationem perventum fuerit, ejus eflè conditionis , utnbsp;^ocus ad indagandum propofitus fui quidem naturk

K.k 2. nbsp;nbsp;nbsp;linea

-ocr page 288-

^6o El EM. CVRVARVM linea Parabolica exiftat; fed quöd nulla tarnen qujeflioninbsp;fatisfaciens defcribi poffit, cum propofitas quantitates,nbsp;eo, ut petitur, modo, conjungi nequeaiit.

Ad demonftrationemautemeorum, quaefupradidlafunt, (ti-matur in curva ID punflum utcunque, veluti D, dudaque D E ipü F G parallela, qu^protrada fecetredam GB inB, occur-ratque diametro G C in C, fi D E vocetur^, cum E B feu A G

fitOD c, amp; B C CD erittotaD C CD ƒ c j hoceft, z-

Cumque ex natura Parabolae quadratum ex D CooFGC redan-gulo, erit quoque ex antediétis zzZD dx. Ac proinde fubftitutis

aiit reftitutis^ ^ ^ ^o^o Zy itemque ~ nbsp;nbsp;nbsp;^ in locum-ipfius

dy amp;ablatis quae propter aequalitatem feinvicemtollunt, ordi-

. nbsp;nbsp;nbsp;1nbsp;nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;ibxynbsp;nbsp;nbsp;nbsp;y hhxx

natisque omnibus, utdecet, erit^—---hx cyzobx--

cc. Quoddeterminandum,demonftrandumqueerat.

Sin autem aequatio fuiffet ƒƒ—'icjZDbx

fada aflumptione fecundum Rcgulam atque operatione uti de-eet, adeandem aequationem perventum fuiflet j fed quoniamc

juxta afliimptionem eo cafu faciendam fuilfetaequalisj— —*—h

idcircoquoquefuppofitis, ut ante, reftaGB non infra fed fupt* redam A E, ut amp; G C non infra fed fupra eandem G B ducendanbsp;fuiffet, caeteraque omnia eodera quo fupra modofuiffent expe-dienda.

„.V nbsp;nbsp;nbsp;• r' , hhyynbsp;nbsp;nbsp;nbsp;zhyx

Siyeroaequatiolit by----ccZD xx ¦——y-icXyC\y*

eft converfa fuperiüs expofitae, aflumpto juxta Regulam v tXgt;

X c,cntxOO)v — ^ —c. Vndefubftitutohoevalorein ad

locum jphusa^, ejufdemquequadratolocoa;ar,expundisqueJis»

qucE feinvicemtollunt, atque omnibus rkèordinatis, fuperiof acquatio fequenti forma induta eritnbsp;nbsp;nbsp;nbsp;CD t' t', aut ((1 lo^®

b fubftituatur ) dyüDvv. ld quod rurfus arguitxquatio-

nem propofitam redudamefle adformulam prxdidi Theorema ïis VII converfira, ac proinde Locum qujefitum effe Parabol^

-ocr page 289-

Lib. II. Cap. II nbsp;nbsp;nbsp;%6t

Ad cujus fpecificam determinationem efto in fequenti figura ipfius initium imtnutabilc pundum A, atque eadem x a pundonbsp;A per redam AE indefinitefeextendereintelligatur, fitqueda-

ducendaprimumeftreda GBipfi AH parallela, ita ut pars reds E A, versus A produdx , ut amp; omnium ipfi squidiftantium, velut A G vel H B lit 00 ccognits. Quo fado, cum qusvis reda,nbsp;qus poffit efle ipfi A E squidiftans Si squalis, ac proinde expri-mi per x, ut, verbi gratia, D H, ad redam G B produda • uti D B,nbsp;squeturar r: ita porroe pundo Gducenda, amp;, fecundumea,

qusinprscedentibus explicatafunt, conftituenda eft Parabolse

diameter ab adverfa parte ipfius G B, quam eft pundum E in reda G C, ut, fi GB indefinite vocetur j,,B C , aliarumquenbsp;omnium ipiii A E parallelarum inter eandem G C amp; redam G B

intercepts partes exprimantur per^. Atque itaquslibet reda^ ipfi A E parallela, quae poffit efle .V ad redam G C produda, ve-

lutiD C, fitoo ^ hoc eft, Cujus qüidemquadratum

cum squaleefle debeat alterisquationis tcrmino , nempe, ^7: ftatim apparet, li Parabola defcripta foret ad diametrum G C,nbsp;“nbsp;nbsp;nbsp;nbsp;Kk qnbsp;nbsp;nbsp;nbsp;cujus


-ocr page 290-

per S fexft.

-téi, El EM. CvRVARVM cujuslatus redum G F ita efl'etafl'umptum, ut redangulaconten-ta fub eodem latere redo amp; diametri portionibus, inter verticenanbsp;G amp; ordinatim applicatas interceptis, torent go ilt;l/, eandem illamnbsp;Parabolam fore Locum qiitelitum. At verb cum ratio redtae GBnbsp;adrecSam BC aliarumque fimilium cognita fit, nimirum, utrfnbsp;ad ^; fitque itidem notus angulus fiib iildem comprehenfus, ut-pote aequalis dato vel affumpto E A H : erit quoque' ratio ipfiusnbsp;GB ad GC aliarumque fimilium cognita, qusc fituti^cognitsenbsp;ad e cognitam. Qtiocirca fi G B fiveE D indefinite fumpta ex-primatur per ƒ, erit G C itidem indefinite fumpta,hoc eft, omnisnbsp;diametri portioj inter verticcm amp; ordinatim applicatas interce-

pta GO ~ ¦ Qux cum in latus redum duda producere debeat ae-quationis terminumiij,idem quoque aequationis terminus dy^ct ^ divifasutpraedidum latus redum reftituatnecefieeft. ac pro-inde fadaeadem divifioneindicablt quotiens latus redum quae-fitumfore^^. HinCjfumptaGFcD ~ pro latere redo, fiaddia-

metrum GC inventam, utfiipra didumeft, defcribatur Parabola GID, fecans redam AH ini: dicocurvamID fore Locum quasfitum.

Sumptoenim in eadempundo utcunque, velutiD, dudaque D E ipfi A H , ut amp; D C ipfi A E parallela, quae quidem D C fe-cet redas AH amp; GBinpundis Hamp;B, occurratquediametronbsp;G C in pundo C: erit A Eooa; ooD H j E DgO/GoG B j A G amp;

HBgocj BC ideoquetotaD C GO .v-pc-f- hoc eft, t'. CumqueexnaturaParabolcCredangulum FGC fitsqualequa-drato D C : erit, fada multiplicatione in ~ , atque 'v in fe

Vi

ipfam,i^j ZOvv. Etfubftitutis autreftitutisa;-f-cq- ^loco

itcmque— in locum ipfius atqueablatisqusepropterae-qualitatemfeinvicemtollunt, ordinatisqueomnibus, utdecet,


hbyy


¦ccCO XX -f-


. by X


2 c X. Quod determinan-


dum, demonftrandumqueerat.

Decaeteris autemcafibus , adprsedidam formulam fpedanti-bus, fupervacuum fiterit plura exponere, cum ex prsedidis facile

explir



-ocr page 291-

Lib. II. C a p. 11. nbsp;nbsp;nbsp;2^^

«XpHcari, determinari, ac demonftrari queant; obfemta folum-modo diversa linearum pofitione, qua ex fignorum amp;_dif

ferentia oriri debet, cumqueomnesfimiliumlocorum cafusmox pergeneralem Kegulam fim exhibiturus.

Exempla reduBionis aquatiomm adformulam Theo-rematis vin.

hhxx


• hx d i^jalTump to juxta


Si squatio fit ƒ jy — nbsp;nbsp;nbsp;CO —

S.egulam z-üliy— ^ gt; erit ^ CO nbsp;nbsp;nbsp;. quo fubftituto in locunt

ipfiusjy, amp; ejufdem quadrate locoj^jy, omiffisque iis , qu* fe in-Vicem tollunt, atque omnibus rite ordinatis, asquatio fuperior fe-^uenti forma erit induta: nbsp;nbsp;nbsp;DO h x -i- dd.


^aa


./

Vude apparet, eandem efle redu^bam ad formuiam Theore-^atts VIII, aeproinde Locum qusefitumefle Parabolam. Ad fiijus particularem defcriptioncra efto in adjunflia figura ipfms xnbsp;**iuium immutabilc pundlum A, atque eadem x a didto pundto A

per

-ocr page 292-

2gt;(?4 Elem. CvrVarVm

per reftam AE indefinite fe cxtendereintelligatur, fitquedatus vel aflumptus angulus, qucmj amp; x comprehendunt, sequalis an-

guloAED. Deinde, quoniani?,CD^—fupra lineamAE

exfurgereintelligatur, velutiED, ducendaquoque eftfiipraliquot; neam AE expundo A redaAB, itanteadem iitratioAE adnbsp;E B , qu£E eft ipfius 2 a cognits ad h cognitam, hoe eft, ut fit uti

2 ad ^, ita A E feu a; ad E B, eritque E B co nbsp;nbsp;nbsp;• idem intellige

dcomnibus alüs redis ipfi E Bpa’rallelis, atque inter A E amp; A B

interceptis, qusequidemfingulsipfi —erunt «equales. Hinc,,

l

quemadmodamexfupradidispatet, fi terminus «/«sf inaequatio'* ne deficeret, prsdida A B Parabol» diameter foret, ejufq'^®nbsp;vertelt pundum A, amp;, pofita ratione A E ad A B, ut 2 4 ad

tusredumipficorrelpondenseffet 30 nbsp;nbsp;nbsp;lam verb cum redan^

gulum, quod fub latere redo amp;portione diametri, inter vertiquot; cem atque ordinatim applicatas intercepta, continetur, »quanbsp;efle debeat bx dd-, manifefturaeft,fi, iifdempofitis, diatn^^

-ocr page 293-

Lib. II. Ca p. II.

A B versus A producatur ad G, ita ut reóèangulum fub przdido latere redto amp; parte G A contentum fit ZOdd, reSam G B qus-fitam fore diametrum, ejufque verticem prsdiftum G punftum:

ac proinde S^dd^tt prsdidum latus reöum,hoc eft per ~ , dt-

vifum sequari longltudini G A, ideoque G A fore oo . Quare

ft diametro G B amp; latere reifto G F CD nbsp;nbsp;nbsp;in dato angulo Para

bola defcribatur GD d, fecansAIipfi EDparallclaminI: di-cocurvaml Dlt;sifore Locum quxfitum.

Verum obiter hicquoque notandum venit, prsdidtum verticem G etiam inveniri hoc padlo: ft nempe E A producatur ad C,

• nbsp;nbsp;nbsp;ddnbsp;nbsp;nbsp;nbsp;^

itautAC fit CD ) ac deinde per pundlumCipfiDEparallela

ducatiirCG, occurrensproduSseABinG: eriteniraineodem illo concurfus punóto vertex qucefitus.

Tiemonfiratio.

Sumaturinprxdilt;aacui-vapun(aumutcunquc, velutiD, du-aaque DE in angulo A’ED, datovel affumpto tequali, fecantc

diametrum G B in B; erit, ex conftru(ftione, B E CD ~ ; ideoque ftED voceturjjCritDBcD/'—feu2;,;FGcD ^^,G Aoonbsp;—ABcd —, totaqueGB CD ^-^-—.Atcumexpropric-tateParabolseD Bquadratum fit2qualere(ftanguloFGB, erit,nbsp;faöa multiplicatione ipfius z in fe ipfam,atque in — f -f-

^zZDdd igt;x, Vnde fubftituto y — — loco z, obtincbitur

hxy


hhxy


•¥bx


CX)-


Quoderatdemonftrandum.

Quomodo autem pro cafu hujus exempli converfo Parabola defcribenda fit, ex compatatione ejufdemcum antedidlisfacilenbsp;eft colligere.

¦car.

SitEquatiofuerit ~

IL


LI


aflum-


-ocr page 294-

Elem. Cvrvarvm

aflumptojuxtaRcgulamvZD nbsp;nbsp;nbsp;|c,eritxODv

quo fubftituto in locum ipfius x, ejufdemque quadrato loco a; ablatisque iis, qux fe invicem deftruunt, atque omnibus rite or^nbsp;dinatis, tequatio fuperior fequenti forma erit induta.

ccCO vv.

Vnde apparet eandem efle rcdudlam ad formulam prtedidli Theoremaiis VIII converlim , ac proinde Locum quaeficum efiènbsp;Parabolam. Cujus fpecifica determinatio (fuppofitis, ut in adjiiR'nbsp;óla figura, AE indefinite aflumptam efle quantitatem incognrnbsp;tamA:, atquecumalteraj conftituere angulumsqualem angulonbsp;E A C vel ejufdem ad binos reftos fupplemento) quoniam ex jamnbsp;ante explicatis quafi fponte profluit, idcirco eam adjunda figuranbsp;breviter indtcaffe fuffecerit.

determinatio Loei.

A E indefinite oo x.

E D omnesque ipfi parallelse CD ĥ

^Koo^cjoCH , quia K H parallela A C.,

lt;D

/K

Te

Vt^ad^, itaKHfeujadHB : undeHB fitx ^ gt; amp; D BOO'*’

30 7/.

Vt^.adfj itaKHfeujyadKBtundeKB (in qua diameter)

X

a

ah

hy divifum per ^, reddit ^ : unde latus redum F G fitx • xf lt;7, nempeterminussequationisin totumtognitus, divifospef

-ocr page 295-

±6y

Lib. II. Ca p. IL

, nempe per latusreöum, rcddit ^: uiideK G fitx

qiieGBoo — - .

xab a.

Tiemonflratto.

Redangulum F G Bcx)B D quadrato,ergo | rc nbsp;nbsp;nbsp;301/1/, vel

byZDvvjcejhoc éi, égt;j CO x x nbsp;nbsp;nbsp;¦

¦— ~ c c.

Quocirca deletis delendis , faöaque decent! tranfpofitioncj fiet — -4- b r —nbsp;nbsp;nbsp;nbsp;00 xx-i-c x. Qubd

eratpropolitum.

Exemplum reduBionis aquationum adformulam Theorematis IX.

lb.

cc, Affumatur

h X

Sit xquatioj^ nbsp;nbsp;nbsp;— cyZO ax-

juxtaRegulam^GOjI' T^ —^c,eritque^03?,—^ ^c. Quo fubftitato in locum ipfiusj', amp; ejus quadrato locojjy, fient aequa-tionistermini,utfeqüitur:zzC0 ax--— — 1 cc. Facilitatis

ergo pro a— - .fcribatnrd,fupponcndo lt;jefle majorem quam -

eritque sequatio zzCO dxIcc. Et apparet eandem redudtam eflead formulam Theorematis IX, proptereaLocumquseil-tumefl'eParaboIam, quamexiis, qusjamexplicatafunt,deter-niinareacdercriberefacilHmumeritjutexfequenti figura iisquenbsp;fuper eadem breviter annotata funr, coHigere licebtt.

Tdeterminatio Loci.

Sit initium immutabile ipfius x pundum A.

A E indefinite 30 X.

E D omnesque ipfi parallelle OO/-

E A K vel A E D, angulus quernx amp;jr comprehcnderc debent.

LI 2 nbsp;nbsp;nbsp;AK


-ocr page 296-

i^8 E L E M.

A. K- 00 ” c*

K H parallela ipfi A E.

Vtz^adAitaKHfeuAradHB :undeH Beritoo —

' nbsp;nbsp;nbsp;xa

Vt2 azAe, ita K H feil Af

adKB : undeKB (in

, reddit

ex xa *nbsp;e X

xa, unde latus re-

e

öum, quod fit F G, erit

e

\cc divifum per red-unde K G fit

ex

ïa


3 cce 8a d ‘

Hinc fi GB diametro amp; latere reéio F GperverticemGde-fcripta fit Parabola, fecans KHinI, erit ID Locus qusefitus.

TDemonjiratio.

Efto pundum D utcunque fumptum in ID, amp; D E duda parallela ipfi A K, qus fi vocetur^; erit H D ODj — i c, ac D B 00

j hoe eft,?:. Cujusquadratum cumsequeturreftan-

fulo F GB, erit z.eiTD dx—Icc, hoe ék, yycy-j^^cc-^

xy hex , hhxx nbsp;nbsp;nbsp;igt;cx ,nbsp;nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;-

--1T nbsp;nbsp;nbsp;Aepromde, fiutriH'

que demantur tequales, terminique rite tranfponantur, habebitur

I b X y nbsp;nbsp;nbsp;hhxxnbsp;nbsp;nbsp;nbsp;^ -i

77T -j- —cyZDcix— nbsp;nbsp;nbsp;—‘CC. Quoderat propofituai-

Atque hujusquidem exempli converfum, utamp;caeteros cafu® hue fpediantes, ex iis, quae jam dióia funt, fimili modo reducere

atque refolyere non difficile erit.

Exent-

-ocr page 297-

Lib. ÏI. Ca p. II.

Exem^la reduBionis aquationum adformulam Theorematis X.

Sisquatio fit ajjy ZObx, five, quod idem eft, nbsp;nbsp;nbsp;.— ay-\-

bxZDo, aflumptojuxtaRegiilamx:,GQ7'—erit^oo Quo fubftituto in locum ipfiusj', amp;ejufdem quadratoloco y^,nbsp;remanebit ?,?. 00 iaabx. Vndcapparet,eandemcfleredu(5tamnbsp;adcafum Theorematis X, ideoque per ea, quae ibidem funtde-nionftrata, Locum quaefitum effe Parabolam.

Ad cujus fpecificam determinationem efto in appofita figura ipfius X initium immutabile punöum A, eademquear fe indefinitenbsp;ab A versus Eextendcre intelligaturj fitautem datus vel aflum-ptus angulus,quem^ amp; x comprehendunqaequalis angulo E A K,

autipfius adbinosreiftoscomplemento. Deinde, quoniam?.af-

fumptaeft 00/—fi/fupra rediamAEexurgereintclligatur, ducenda quoque eft fupra ipfam redta K G ipfi A E parallela, itanbsp;ut A K omnesque ipfi sequidiftantes inter A E amp; K G intercepts

fint X Quo fado, fi juxtaRegulamfiatK G x , eadem-

que fumatur proParabols diametro, adquamordinatimappli-cats fint ipfi A K parallels, cujusque latus redum F G fit x ^ r eritipfius portio deferipta GDI, qus inter verticem G amp; pro-dudam A K intercipitur, Loews qusfitus.

LI 5 nbsp;nbsp;nbsp;Etenim


-ocr page 298-

%jo Elem. Cvrvarvm

Etenim affu^pto in curva GDI punfto utcunque, veluti D, dud^ue D E ipll A K parallela, qu$ fecet diametriim K G in B,nbsp;fieadem D E voceturj: erit D Bcx) ƒ—jafeaz., ac GB five

GK — KBcö ^—X. Hinc,cumexnaturaParabolesquadra-

turn ex BD fit sequale reftangulo F G B, erit zzCO^aai^x, hoe—a^ ^aaooégt;x, üvejj^ay-^bxZD o»nbsp;fiveetiamlt;«^—yyZO bx. Quoderatpropofitum.

Sijequatio fuerit nbsp;nbsp;nbsp; ^/ — ce03nbsp;nbsp;nbsp;nbsp;— xx, five, quod

idem eft,dj — ecOO o : afllimpto juxta

Regulamt'OO x-—^ ,erItA:OD nbsp;nbsp;nbsp; Quo fubftituto in lo

cum ipfius;v, ejufdemque quadrato loco xx, fiet, omnibus rite ordinatis, ccdy^Dw- Vndeapparetcafumefte Theorema-tisX converfim, ac proinde Locum quaefitum effc Parabolam.nbsp;Quae quidem ut fpecifice deferibatur, efto ipfius x initium immu-tabile A punfl;um,intelligaturque eadera^e i'e extendere ab A versus E indeterminate, fitqueangulusdatusvelaflumptus, quern/

amp; X cornprehenduntjsequalis angulo E A H aut ipfius ad duos rectos complcmento.Deindefumatur in A H reifta A CzD^, dt*quot;

caturque ex C redia C F ipfi A E parallela, atque in eadem fumpta C G, quae fe habeat ad C A, ut cognita ^ ad ^ cognitarn, hoc eft»nbsp;utfituti^ad^, itaACadCG, agaturAG, eaque pro diametronbsp;Parabolae fumaturjquae per verticem G versus A erit deferibenda.nbsp;Porro cum in triangulo A C G ob rationem cognitarn laterutn

A C,

-ocr page 299-

Lib. II. Cap. 11. nbsp;nbsp;nbsp;iji

AC, CG, cognitum angulutn Ccomprehendentiutn, utpote dato vel aflumpto aut ejufdem ad duos redos fupplemento aequa-lem, cognita item fit ratio, quamhabet A Cad AG, qusefit

Ut ad f j erit, A C exiftente QD j A G CD ^ ¦ Per quam fi

terminuszquationis,intotumcognitus, nimirumf c, dividatur,

orietur^*^ pro latere redo. Acproinde fifiatGF CD ~,eritGF

latus redum qu^fitae Parabolae, diametro G Acorrefpondens atque kcirco fi ad didam diametrum, didumquclatus redumnbsp;Paraboladefcribatur,ut GDI, fecans AE ini idicoID G cur-Vam efle Locum quaefitum.

Sumptoenimin eapundoutcunque ,veluti D, dudisqueD E ipfi AH, ac D B H ipfi A E parallelis, fi eadem D E exprimaturnbsp;per^, erit quoque A H CD ƒ. Cumqucfitut ACadCG, id eft,

ad ita A Had H B : erit H B CD ~ gt; ideoque cum D Hfeu A E fit CDA;,erit D B CD a; •— ^ feunbsp;nbsp;nbsp;nbsp;Similiter cum fit ut A C ad

a

A G jhoe eft, utlt;* ad e, ita A H feu v ad A B: erit A B ZO ~ 8c

^ nbsp;nbsp;nbsp;a *

GA—ABfeuG'BcD^-

aa

. Hinc cum ex natura Paraboles

rcdangulumFGBfitsequalequadratoexBD ,erit, fadamulti-plicationeipfiusF Gfeu— inG Bfeu nbsp;nbsp;nbsp;ipfiusBD feu

ï» infe ipfam,c c—dyZHv v. Hoc eft,reftituto x-—loco erit

•XX.

Quod determinandum, demonftrandumque erat.

Obiter autem amp; hic notandum , ut ex antedidis quoque facile eftcolligere, aliter etiam diametrum G Aatquelatus redum G Fnbsp;itidagari potuifte, hoc modo:

Cum A H indeterminate fit CD/, juxta primum Theorema hu-jus ita ducatur A G,ut reda H B, quemadmodum amp; quEclibet alia

ipfiAEparallela, quae inter A H amp; A G intercipitur, fitCD ^5 ponaturque ratio, quae eft inter A H amp; A B fimilesque, ut ad f:nbsp;ideoque cum A B indeterminate fit CD^,terminus aequationis dj^

per

-ocr page 300-

EleM. CvRVARTMj

ad


pereandetndivifasoftendetlatusredumfedionisF G X — • Siquot; militer terminus squationis cc perprsedidura lams redutn feunbsp;^ divifusdabitquotientcm ^-proqusfitaAG.

Plurahic exempla fubjungere fupervacuum foret, cummox omnes omnino cafus poffibiles generali regula annotate ac de-monftrare animus fit.

Porrö quamvis Regulas capite primo explicatas par-ticularibus ibidem exemplis feu cafibus in hypothefi non illuftraverimus, neque etiam id auc hic aucin fe-quentibiis ullo modo neceflarium ducamus , quippcnbsp;cum unufquifque, qui Regulas ipfas reftè perceperit,nbsp;eafdem quibuflibet propofitis exemplis feu cafibus innbsp;hypothefi facile applicare valeat: quandoquidem tarnen libro primo infignes quafdam proprietates Parabolas, Hyperbolae, atque Ellipfis confultö praetermifi-mus, ea mente, ut in hoe libro fuis locis permodumnbsp;Problematum non incongruè proponi ac demonftrari,nbsp;fimulque tanquam propolitarum Regularum particu-laria exempla haberi pollênt, earundem explicationemnbsp;hic amp; fub finem fequentis capitis fubjiciemus.

Problema I.

‘Propvjitio II.

Datis punfto amp; line^ reft^, in plano per utrumquc diKÏboaliud punftum invenire, a quo binaeredae, altera ad datum pundum, altera ad datamlineam perpen-dicnlariter dudae , fibi invicem fint aequales : amp; quo-niam infinita funt ejufmodi punda, quae quaeftioni In-tisfaciunt, Locum determinate ac defcribere, in quonbsp;cunda amp; fingula reperiantur.

Sit datum pundum A, amp; data pofitione reda linea B C, oporquot; teatque in plano quod per utrumque ducitur,aliud pundum inve*

nircgt;

-ocr page 301-

Lib. II. Ca p. II.

Xiire, qucmadmodumD j itautduftae reöseD A, DF, quarum hxc ad datam B C intelligicur perpendicularis,fibi invicem aequa-lesfint.nbsp;nbsp;nbsp;nbsp;^

Du£taperpendicular! A E, quaevocetur^j, acfuppofitisjuxta Regulam binis lineis EF, FD incognitis atque indetertninatisnbsp;datum anguliim reflum E F D comprehendentibus tanquam co-gnttis ac determinatis, quarum prior E F vocetur x, ac pofteriornbsp;Ed nominetur^; fi dudla praeterea intelligatur A G ipfi EFnbsp;*quidiftans, erit in triangulo reftangulo A G D bafls A D co ynbsp;utpote CD dudae D F; latus verb A G feu refla E F OO at , amp; G D,nbsp;five,( fi punftum G cadat inter Damp;F)FD'— AE, aut ( fi pun-öm-nD inter F amp; G cadat) A E—F D ZDy~a. Vnde, cumqua-dratum bafis aequale fit binis laterum quadratis fimul fumptis, s-^uatioeritjy CD xx jr j— z aj ArAO.-, hoc eft, ablatis iis quse fenbsp;gt;nvicem deftruunt,omnibusque rite ordinatis,crit 2 ay'aa-j^ixx.nbsp;Qui quidem cafus eft Theorematis noni hujus libri converfim,nbsp;proinde Locus quaefitus eritlinea Parabolica. Ouare fi juxtanbsp;^lt;frs II,nbsp;nbsp;nbsp;nbsp;Mmnbsp;nbsp;nbsp;nbsp;€3,

-ocr page 302-

474 E L E M. C V R V A R V M

ea,qu3e ibidem expofitafunt, exE ducatur redtaE I indefinite ex-

tenfa atque ipfi FD squidiftans ; amp; ab eadem auferatur recia

EHcx)~ »ideft, 4*3: eritdefcribend* Parabolse diameter in di—

IA nbsp;nbsp;nbsp;^

ö:a EI, ( quas qiiidcm diameter axis quoque eft,propter angulum E F D redum ) vertex autem in H, ac parameter go 2 4. Vnde,.nbsp;per ea quï libri primi capite primo expofita funt, Parabolamnbsp;ipfam defcribcre facillimum erit. Gumque porrö axis pundum A,nbsp;utpotequodab FI verticediftat quartaipfmsparametriparte, idnbsp;iptumfit, quodvulgö Parabols Focus feu Vmbilicusnuncupa»-tur, apparet ex prsmifïis rede inferri,qu$ fequuiuur.

Corollarium 1.

Quae ab Vmbilica ad quodlibet Parabolae putiftum reóla ducitur aequalis eft axis portioni per applicatairï'nbsp;ab eodem punélo abfciflae amp; quadrante parametri pernbsp;verticem producftae.

Conftat enim ex antedidis redam A D, utcunque aflumptum fuerit incurva pundum D, fi per idem illud ad axem ordinatinanbsp;applicata fit DI, aequalem efle perpendicular! D F, hoc eft, redaenbsp;IE , nempe axis portioni, per applicatam D I abfciffae, amp;pcrnbsp;verticem H, longitudine FI E GO id eft, quadrante parametri?nbsp;produdte.

2.

Corollarium

Maiiifeftum quoque eft ex aiitedidis, fi pofitis qusB fupra, amp; produdi F D, uti ad M, per aiïumptum puO'nbsp;6tum D contingens dult;fta fit, ut L D K, angulum F Dnbsp;five M D L angulo A D K aequalem elTe.nbsp;ï fct 1 Occurrat enim contingens L D K axi produdo in K, eritque *nbsp;^ reda I Fi ipfi Ei K, ideoque ( squalibus H E, A H utrinque addiquot;nbsp;^ E, hoe eft, A D, ipfi A K squalis; ac proinde ^nbsp;i per f gulus A D K angulo A K D,hoc eft, angulo F D K five M D L*quot;nbsp;primi, qualis fit neceflè eft.

-ocr page 303-

C A P. III. T III.

TErtio autem cafu ftipra exprefïb, cüm nempe quan-titatum incognitarum utraque ad quadratum afcen-dit , five altera in alteram duéla in aequationc reperi-tur, neque aequatioad terminos magis fimplices redu-•ci poteft , ad aliquam fequentium formuiarum deven-•tum erit;

i.yxzoff

11.co XX—ff

III. yy-


1 nbsp;nbsp;nbsp;zoff—xx.

XI.

Theorema T*ropoJitio li.

Si seqnatio {nyxcoff. Locus qusefitus eft Hyperbola.

Sit enim, ut in prxcedentibus, ipfius x initium immutabile A

punóium , atque ea-dem illa x per rcöam A E indefinite fe ex-tendere intelligatur jnbsp;litquedatus velaflum-ptus angulus, q.uemjnbsp;amp; X comprehenduntynbsp;squalis angulo E A B,nbsp;aut ejufdem ad binosnbsp;reótos fupplemento.

Deinde fumatur in A E reöa A C co/,du-caturque CG cidemnbsp;3ïqualis ac ipfi A B parallela, defcriptaque ' per punftum G at-

Mm2 nbsp;nbsp;nbsp;^ ^^^CoroUd

II 12, wfw» ca^.uh.lib.mmihujastraditafttm.


-ocr page 304-

zyS Elem. Cvrvarvm

que Afyoiptotis AE, AB Hyperbola GD: dicocurvam GD efle Locum quaefitum,

* per ^ primi hu^nbsp;JUS.

Sumatur enim in eadcm curvapunélum utcunque, velutiD, diiiSaqueD E ipfi A B parallela, critexnatura Hyperboles * re-dtangulum A E D reftangulo A C G, hoc eft, quadratoex A Cnbsp;squale. Hinc, cum A E fttaflumpta pro incognita qu^antitatc.v»nbsp;fiE D voceturj)f,eritjArco//. C^od determinandumdemon-ftranduinque erat.

XIT.

^ro^ofttio 13.

Sisquatio fit— oo xx—ff , erit Locus qujefitus li-

o

nea Hyperbolica.

Autenim/ipfi^tequaliseftautinaEqtialis, amp;ftxqualisfit, erit fuperior squatio eadem ac ft cffet^j 00nbsp;nbsp;nbsp;nbsp;—ff (quod femel mo-

nuiftefufficiat).Ac T*nbsp;nbsp;nbsp;nbsp;facile apparetjfi i-

pftusA:initiumim-jy/ mutabile fit pun-^ (Sum A, atqae eadem X fe in linea AE ab A versus Enbsp;indefinite extende-reintelligatur,fit-que angulus da-tus vel aflumptus,nbsp;quern ƒ amp; A;com-prehendunqaequa-lisangulo AGE,

a per ea qu£cap.nbsp;ult.priminbsp;hujusnbsp;cjienfanbsp;pnt.

quod fi tarn A G quam A C fiant OD ƒcognits, ac G F fumatur 00 G C, centroque A, amp; transversa diametro C G ipfi G F late-ri relt;So five parametro jequali defcribatur * Hyperbola, utGD,nbsp;eandem curvamG D fore Locum quaefitum.

Sumpto enim in ea puncSo utcunque, veluti D, duftaque D E per 10 ipfiF G parallela, erit ^ex naturaHyperboles, cumCGamp;GFnbsp;fupgonantur aequales quadratum ex D E aequale redlangulo


-ocr page 305-

Lib II. Cap III. nbsp;nbsp;nbsp;277

C E G. Hine, fi D E vocetur^, cum ex hypothefi C E feu A E A C fit ZDx f, amp; G E five A E—A G zox—f, entyy 33

XXff.^

At veto fi /amp;fint inaequalesjapparet efle, ut /ad^.ita xx—ƒƒ Acproinde fi juxtaea, quaefijpra expofitalunt, non jamnbsp;parameter G F diametro tranfverfe C G sequalis, fed ut /ad

ita fiat tranfverfa diameter CG adGFparametrnm, cteteraque omnia, ut fupra, eodem modo quaefito eri t fatisfadium.

Eft enim '¦ ex natura Hyperboles, ut EG ad GitaED' ic-quadratum ad C E G redangulum, hoc eft, ut^^ad/, ita^^ adf’'''quot;'^ XX'—ƒƒ, unde, revocandoproportionem adaqualitatem, crit'^*^^'nbsp;hy ZDgxxgff. Acproindefiutraquehujus tequalitatispars

^ividaturper^,erit ^ GO .vat.ff. Quod detecminandum,

^emonftrandumqueerat.

Theorema XIIÏ.

Tropojitio 14,

Si squatio nbsp;nbsp;nbsp;—ƒƒ oo ^ , crit Locus quaefitus

%perbolai

. Adcujus determinationem fpecificam eftoin appofita figura ^pfius X initium immutabile punöum A, ipfaque x le ab A versus

Mm3 nbsp;nbsp;nbsp;tin


-ocr page 306-

2,78 Elem. Cvrvarvm

E inlinea AE indefinite cxtendcre intclligatur, fitque angulus quemjy amp; A'comprehendunt sequalis angulo E AG autejufdemnbsp;ad duos re(S:os fupplemento. Deinde,cumfitut/ad^, ita^^—ƒƒ


ad AT AT, ftatimapparet, fitamAGquam AC fumantur xquaies ƒ cognitaSjfiatqueut/ad^jita C Gad GF (quaequidem G F fitnbsp;ipfi A E parallela ), ac poftea centro A, tranfversa diametro C Ggt;nbsp;amp;parametro GF HyperboladefcribaturGD, eandemcurvamnbsp;G D fore Locum quaefitum.

Sumptonamque ineapun(5i:o utcunque, velatiD^ dudlaqaö D E ipfi A G, ac D B ipfi A E parallela, fi eadem D E vocetury»nbsp;eriiC Bjhoc eft, D E 4-A CjCD^ /j amp; B G ,fiveD E—A G,nbsp;’ jöq 10 3QJ—ƒ, ideoque C B G redangulum CD/7—ff- Dein cum' einbsp;fnmihu- natura Hyperbol» fit Ut C Gad G F, hoe eft, exhypothefiut/adnbsp;ita redtangulum C B G ad D B' five A E quadratum, id eft, it*

/x 'J» ^

yy—ff ^^xx'-tntgjy-^.gff ZD lxXy\iocc{y^yj'^ff‘Si g '

Quod demonftrandum, determinandumque era*.

-ocr page 307-

^79

L 1 B. n. Gap. III. Theorema XIV.

*Pro^qfitio if.

Sisquatiofit^ aoff—xx, eritLocus qujefitusEl-lipfis.

At veró cum Ellipfeos fpecies, qua: latera re(ftumamp;: tranfverfum sequalia habet , angulumque quemordina-tim applicatJE faciunt ad diametrum reftum, fit Circulinbsp;circumferentia: palam fit cafu propofito Locum quaefi-turn etiam Circuli peripheriam eflè pofle.

Hincad prjedióli Loei determinationetn eftoinappofitafigu-ra ipfius x initium immutabile A punöutn, atque eadein x fe per lineam A E ab A versus E indeterminate extendere intelliga-

tur, fitqueangulüs, quem ƒ.amp; compreHendunt, squalisan-guloAGF. Porró cum fit ut /ad^, ita nbsp;nbsp;nbsp;ad vy: fa

cile apparet, fitam AGquam ACfumantursquales/cogni-t3e;fiatqueut/ad^,itaCGadGF,accentroA, tranfversadiametro C G, amp; parametro G F ‘ EUipfis defcribatur G D C' nbsp;nbsp;nbsp;7

Cr I CoA


candem curyam G D C fore Locum quxfitum. nbsp;nbsp;nbsp;Carol. 13

Sum-


hujui, ut amp;^er ea nbsp;nbsp;nbsp;circa fnem cap. ^ ejufdem lih. ir^ita/iint.

-ocr page 308-

180 El EM. CVE.VARVM

Sumpto namquein eapundto utcun^ue, velutiD, duöaquc

per 15 primi hu~nbsp;jus.

D E ipfi F G paral-p lela , erit ' ex natu-ra Ellipfeos ut F G ad G C, ita E D qua-dratum ad C E G re-(Sangulum. Hoc eft,nbsp;ft E D vocetur V, cumnbsp;CE fit CD ƒ 4-.V, ^nbsp;E G CO ƒ—ar, eritutnbsp;^ ad / , itz y y ad f f

—ara:,unde.^ CO//

i?

IG- — ^

pofitutn.

Caetcrvim liquido conftat, fi C G amp; G Fnbsp;a:quales fuerint, hocnbsp;eft , Ü I CO g , quodnbsp;etiam C E G redtan-gulum quadrato E Dnbsp;jequalefitfutumm. IdeoquefianguIusCGFfitredus, curvaranbsp;GDC fore Circuli circumferentiam.

Regula uni’verfalls , modafque reducendl omnes ^quationes^c^Uie ex convenienti ope-ratione exiftmt, cum Locus Del Hyperbola eft, Del Ellipfis, Del Circuli circumfe-rentia, ad aliquem quatuor cafumn pra-cedentium , totidem Theorematibus jamnbsp;explicatorum.

Si conringat, uEquantitatum incognitarum non mo-do una in alteram , autnon tantum alteriitra vel utra-que in le duda, fed amp; vel hcec, vel ilia, vel utraque u-nius pr^terea dimenfionis in cequatione reperiatur , conflituens planum cum alia, five cognita five incognita.

-ocr page 309-

Lib. II. Cap. III. ta, fiveetiam cum partim cognita amp; partim iiicogniranbsp;quantitate : oportet loco incognitarum , aut illarumnbsp;alterutrius, affumere alias vel aliam, quas ipfas exce-dunt, vel ab iis deficiunt; idque integr^ quantitate,nbsp;qu^ cum ilia incognita , in cujus locum nova non eftnbsp;aflumpta, planum conftituere reperitur, ft nempe incognitarum neutra in fe ipfam in sequatione dufla fit;nbsp;fin fecus, dimidio tantum ejus quantitatis , quas planum conftituit cum incognita, in cujus locum afiiim-ptio fafta eft, cafu utroque juxta differentem affeftio-nem per figna vel —, quae praefiguntur iifdem illisnbsp;quantitatibus, ita ordinatis , ut cum incognitis ab ea-dem aequationis parte reperiantur. Quo fadlo, amp; reiterate , ubi opus, ft ad formulas Parabolarum, capitenbsp;fecundo expofttas perventum non fuerit, ad aliquemnbsp;quatuor fuprapolitorum cafuum redufta erit aequatio,nbsp;ac proinde ipft convenientem Locum determinare acnbsp;deferibere, per ea quae fuperius explicata funt, baud difficile erit.

EiXefnpluntTeduBioms aquationum adformulam

Theorematis XI.

Siasquatio ivLcntyx—cx-^rhyZO raflumptos: ZO)'—c, amp; vzQx-\-h,tnx.7i-gt;tcZDy,nbsp;nbsp;nbsp;nbsp;—hZDx.

Vnde ii Iccundum Regulam ubiqueinsquatione loco^fub-ftituatur z.-h c, nbsp;nbsp;nbsp;z, x c x—c x hz.' hcZXgt;ce,üwQz.x

hcC0ee;a.c rurfus iiloco ipfius Arfubrogetur — h,entz.v—¦ hz. hz. hczoeetide{k,zvZDeehe. aut, (fi loco termininbsp;ee—hcy quiin totum cognituseft, fenbatur/f) zvzdff. Etnbsp;apparec «quationem redudam efl'e ad formulam Theorematis XI, ac proinde Locum quaefitum efle Hyperbolam.

Ad cujus fpecibcam determinationem ac deferiptionem eftti in appofita figura initium ipfius x imroutabile punftum A, atquenbsp;eadem AT per redam AE indefinite fe extendcreintelligatur, fit-que angulus, quemj amp; x comprehendunt, tequalis angulo E A K

Pars II, nbsp;nbsp;nbsp;N nnbsp;nbsp;nbsp;nbsp;aut

-ocr page 310-

28^ Elem. Cvr-Varym

autejufdemadduosreftosfupplcmento. Deinde,quoniam2:eft 037 — c\ (17fupralineam AEexüirgereconcipiatur, ducendanbsp;quoque cftmpraeandem reétaKB ipll A E parallela; itautparsnbsp;reótï A K, omniumque ipfi xquidiftantium, inter A E amp; K B in-tercepta, veluti A K, xquctur ecognits. Porro, quoniam v eftnbsp;tD ^ 4producenda eft ipfa B K per K ufque ad G,ita ut K G fit

H’i


00 h. Quo fado, erlt G centrum ipfius curvs, amp; G B una Afym-ptotamp;jn, eritque altera ipfi AK parallela,utGH. Vndefijuxta Regulam prsedidi Thcorcmatis XI in reda G B fumatur G Cnbsp;qualisƒcognitx, ducaturque C F eidem G C sequalis, ac parallc'nbsp;la redïE A K vel G H, atque per pundum F, Afymptotis G B amp;nbsp;G H, five Afymptoto G B atque ad axem G F, Hyperbola defcrEnbsp;batur F D : dico curvam F D fore Locum qutefitum.

Sumpto enim in ca pundo utcunque, veluti D, dudaque D L ipfi A K parallela, quaefecetredam KBinB, fieadem DEvO'nbsp;cetur7, critDBfiveDE — EBxj—c,ideft,?:. Eftautem^nbsp;G B five AE GKooa: ^, hoe eft, t/. Qiiare cum ex natur*nbsp;Hyperboles redangulum G B D aquetur G C quadrato , eritnbsp;quoquea:'z/00//. autreftitutisy—elocoipfius inlo'nbsp;cum ipfius 'y,atqueee — ch loco ƒƒ, erit7 xcx hy—chCPnbsp;eech, hoe eft, jx — cx hjZOee. Quoderat propo'nbsp;fitum.

Exem'

-ocr page 311-

Lib. II. Cap. III. nbsp;nbsp;nbsp;^85

*

ExemPla reduBionis aquatiomm adformulam Theorematis XII^XIII.

Si sequatio Cityy nbsp;nbsp;nbsp; a «7 Xnbsp;nbsp;nbsp;nbsp; ex dd, aflumpto

!t, GO7 4- — 4- c, erit^ x s: — ^ — c, eoque fubftituto in locum iplius^j atqueejufdemquadratolocojj, fublatisque iis, quaefe

‘ nbsp;nbsp;nbsp;• j nnbsp;nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;hhxx zbcx ™I I JJ

invicem deftruunt,erit z.z-----ccCO

' nbsp;nbsp;nbsp;a anbsp;nbsp;nbsp;nbsp;anbsp;nbsp;nbsp;nbsp;^

xbcx


Etfaöacongruatranfpofitione,?.z.ZD4- —^ •\rex ^

dd-\-cCf hoc eft, multiplicatis omnibus ^quationis terminis per aa, produóioque divifo per ƒa ip; ut quantitas x x abfquenbsp;C O.-nbsp;nbsp;nbsp;nbsp;rnbsp;nbsp;nbsp;nbsp;. a aex iahcx aadd aocc

iractione remaneatjfiety—j-ry nbsp;nbsp;nbsp;--^ , ,,--1--2--rr7— .

fa bb nbsp;nbsp;nbsp;fa bb ^ fa bb.

Deinde aflumpto v'X)x -^f'^^bb' * nbsp;nbsp;nbsp;quoque 2-

quationis, in quo x unius dimenfionis reperitur, plane evanefcatj^ habebitur ATnbsp;nbsp;nbsp;nbsp;. Quo fubftituto in locum ipfiusx,

atque ejufdem quadrato loco xx, ablatisque iis quae feinvicem tollunt, redu(5la eril xquatio ad formulam requifitam. At veto ut

viteturprolixioroperatioloco nbsp;nbsp;nbsp;f fcribatur 2 /?, ita ut

% ü d XK nbsp;nbsp;nbsp;1nbsp;nbsp;nbsp;nbsp;d ii (Id d A c c , .

fiataEquatio^^_j_ ‘j:gt;xx-\-z hx nbsp;nbsp;nbsp;-• Turn aflTum-

pto t/X x h feu A. X V ¦“ ^,eoque fubftituto loco x in aequatio-ne, ac ejufdem quadrato loco x x; ent nbsp;nbsp;nbsp;x vvhh-i-

apparet, ante omnia hie efle confideran-

, nbsp;nbsp;nbsp;, , r ¦nbsp;nbsp;nbsp;nbsp;' aadd aacc

dum,utrum/;^fumajusquam -, an contra, fi enim

majus fit, erit cafus Theorematis XIIj fin contra, erit cafus TheorematisXIII. Ponatur itaque primo majus, aeproindese-quatio formuk Theorematis XII. Et conftat exindc Locum,nbsp;qusfitum Hyperbolam efl'e.

Adcujus peculiarem deterrainationem efto in appofita figura ipfius a: initium immutabile A punélum, eademque a; in linea A Enbsp;ab A versus E indefinite feextendere intelligaturj fitque angulus

Nn 2 nbsp;nbsp;nbsp;queirt

-ocr page 312-

a84 Elem. Cvrvarvm

qucm xamp;Cy comprehendunt ^equalis angulo E A K aut ipfius ad

duosredèosfupplcmento. Porróquoniam2:CD7 c — gt;

fupra lineam A E cxfurgcre intelligatur,utE D,ducenda primüm eft infra eandem AE reftaKLipliAE parallela; ita ut pars reds A K oinniumque ipfi squidiftantiutn inter prsdidas A E amp;nbsp;KLintercepta,velutiAK, EL,amp;c. squeturccognits. Deinde produda L K ufque ad H, ita ut K H fit 30 ideoque H L indefinite fumpta 30 AT hoe eft, ¦:/,ducatur per H pundutn redanbsp;H G ipfi A K parallela, ita ut K H ad H G fit, ut a ad b. Quo fado , fi per punda Gamp;KredaagaturlineaGKB, habebuntnbsp;omnium ipfi A Kparallelarum partes, qus inter KL amp; KBin-

N,

M/

tercipiuntur (ut, exempli gratia, LB), ad partes ipfius KL, inter cafdem parallelas amp; pundum K interceptas ( ut, verbi gratia, LK) eandem rationera, qus eft inter bSsCax hoe eft, eritut^nbsp;ad^, itaKLadLB , cum utraque fit ut KH ad HG. Ideoquenbsp;cum K L five A E indefinite fumpta fit 30 Ar,erit L B, ut amp; qusli-

bet ipfi parallela, inter KL amp; KBintereepta, 30 nbsp;nbsp;nbsp;: ae proinde

omnis lineafupra AE redam exfurgens, quspoffit efle^incognita, ad redam K B produda, veluti D B five DE EL-I-LB

crit 30j f4.^, hoceft,?.. Vndeapparet,juxtaRegulamliquot;

neam G B fiimendam efte pro Hyperbols diametro, ad quam or-dinatim applicats fintipfi AK feu DB parallels: eritqueejuf-

dem

-ocr page 313-

L I B. II. Cap. III.

dem Hyperbolae centrum G punftum. At verb cum ex ante di-öis triangulum KHG omnino fitcognitum, utpote lateribus I^Hamp;HGanguloqueadHfubiifdem comprehenfonotis, eritnbsp;quoque cognita ratiolatcris KH ad KG, hoc eft, ipfius GMnbsp;(quae per GipfiKLaequidiftans intelligitur ) ad G B, quae fit utnbsp;^ad?'. QiiarecumGMfeu HL indefinite fit-:/, G Bquoque indefinite concepta, hoc eft, quïlibet diamctri portio, inter centrum amp; ordinatim applicatas intercepta, erit ~ . Cujus quidem

interceptae quadratum cum juxta formulam Regulae unum aequa-tionis terminum conftituat, per multiplicationem aut divifionem, Vel per utramque ita reducatur xquatio,ut in eadem quoque idem

quadratum,nimiruminveniatur. Quod quidem ut certa mechodo fiat, prsedidum quadratum redse GB indefinitecon-ceptse, hoc eft,nbsp;nbsp;nbsp;nbsp;dividattir per squationis terminum, in quo

lt;2/1/five fimpliciter, five alia fradione affeduminvenitur, ac per inventuni quotientem totaxquatio multiplicetur. ut in fupra po-

fitoexemplo,fiii^ dividatur peri/i/, Set quotiens ~ . quare

r nbsp;nbsp;nbsp;~nbsp;nbsp;nbsp;nbsp;, iidd iiccnbsp;nbsp;nbsp;nbsp;,

per44,itautfiatj^^aQ --— ¦ nbsp;nbsp;nbsp;- Vnde

fi juxta Regulam femi-latus tranfverfum fiat G F vel G C OO ,nbsp;nbsp;nbsp;nbsp;tranfverfi lateris C F ad re-

aa fa-^-bb ' nbsp;nbsp;nbsp;¦*

dumFN,ut«»ad//i-|-^^, amp;iifdemlateribus, diametroqueaC Centro jaminventis Hyperbole defcribatur FD, fccansredamnbsp;A E vel K A produdam in I: dico curvam ID die Locum quge-fitum.

Sumpto enim in eadem curvapundoutcunque, velutiD , du-d^uc D E ipfi A K parallels, eaque produda ut fecet redam KLinL, amp; diametroGBoccurrat inB,fi eademDE vocetury,nbsp;erit ex ante didis D B OD c. Eft autem, ut jam annotatum,G B oo

~ , atque ex hypothefi GF feu G C x ideoque B C X ~ V

tota squatio multiplicanda eft per ii, produdumque dividendura

iihh

gt; ac B F X'

ihh -iidd-

fa-^-bb

Nn 3

V-.

-ocr page 314-

a86

Elem. Cvrvarvm

iihh


gt; amp; redangulum C B F x

~/a ‘l,7‘^ nbsp;nbsp;nbsp;natura Hyperboles NF ad F C, fei*

fa ^^adxtüt, utDBquadratum,hoceft,adpraediSntn

ii hh , i i d d i


tlVV


aa


//VV


fa bb


/K


Jgt;V

Multiplicetur jamutrinque per aa, amp; dividaturper^’i, eritquc ZOW'— hh-^ quot;“TTirrquot;- Deiti reftituto x h loco v,

ja bb'^ ^ nbsp;nbsp;nbsp;---1- ja bb

aazK nbsp;nbsp;nbsp;I , ‘^‘idd-t-a ace .nbsp;nbsp;nbsp;nbsp;eaa zbclt;*

cxmgct^^^^:Xixx ihx nbsp;nbsp;nbsp;5 itemque

, nbsp;nbsp;nbsp;Inbsp;nbsp;nbsp;nbsp;aazKnbsp;nbsp;nbsp;nbsp;, fX 2iïX aadd-t-aacc

fa-\- bb

Porrö muhiplicatis omnibus fQH fa l^b iisque divifisper

bbxx . nbsp;nbsp;nbsp;. xbc

a ‘ aa b X

loco 2 k exurget^-^^x A.- x nbsp;nbsp;nbsp;¦-----

habebitur Z.Z.CO nbsp;nbsp;nbsp; lt;? a; -l^iï dd cc. Ac deoi'

que reftituto^ ^ c loco ipfius z, expunaisque quaefeb^quot; vicem deftruunt ac omnibus rite ordinatis, fiet^^ nbsp;nbsp;nbsp;nbsp; ^‘'/

f X X

X ~e X dd, Quod eratpropofitum.

At verb ponatur fecundb h h minus quam nbsp;nbsp;nbsp;, amp; ni'

_____¦ ÜKK _ u'vv iihh dd ii-^-ccii

pra pofita squatio —^X —--- -rr^rTT- gt;

multiplicatis omnibus ejufdem terminis per/lt;i ^ ac produiSo

divilo


-ocr page 315-

Lib. II. Cap. III. nbsp;nbsp;nbsp;2,87

divifopcr* ijfadaqiie decent! tranfpofitione, eadem cum fcquenti Kz.~-dd—ccnbsp;nbsp;nbsp;nbsp;^ — mnhip. pa fa ^ ^ ac di-

vir. per«*, id eft, nbsp;nbsp;nbsp;• erit formula Theorema-

tisXl 11, unde Locus qu^fitus iterum erit Hyperbola. Adcujus fpecificam determinationem amp; defcriptionem, poftquam ut innbsp;praecedcnti figura duöx funt lineas A E, A K, K L, K H, H G, amp;nbsp;GKB: eritquidem,utfupra, G centrum, at verb non erit diameter in lineaGK, fed, juxtaRegulam, inlineaHGprodu(5ta

ad partes G, ad quam ordinatim applicats fmt ipfi GKB paral-lelcE , eritque juxta eandem Regulam dimidium tranfverfae dia-

metri,nempeGF velG Cjccqualedd cc ——bbhh^

ratio diametriadparametrumut nbsp;nbsp;nbsp;Quare fifiat, ut

^ ^ ad rG ita C F ad F N, qu£e quidem F N ipfi G K B *qui-diftans fit, erit F N parameter : ac proinde ft centro G tranfversa diametro C F amp; parametro F N Hyperbola defcribatur F D fe-cans ipfara AE vel KA produélam in I, erit ID curvaLocusnbsp;quaefitus.

Sumpto enim in eadem curva punfio utcunque, velutiD, du-öaque D B ipfi A K ( five G F ), amp; D M ipfi G B parallela, ft

ED

-ocr page 316-

^88 Elem. Cvrvartm

ED voceturj, erit, utfupra, DB five MG 30?:, amp; BG five DM CD Cumque fit G F vel G CcoYdd cc~^‘^^^~^^^ i

erit CMgoc '/ d d cc nbsp;nbsp;nbsp;^ amp;MF X

dd cc - nbsp;nbsp;nbsp;, ac propterearedangulum CMF X

h/

Quare cuni ex natura Hyperboles fit ut F N ad F C, ita D M qua' dratum ad CMF teftangulum, hoe eft, ut*i ad ft*

jj fahh hbhh . nbsp;nbsp;nbsp;j j

ad?:,c—ddcc —-: entquoquex:?;—ddCf

fahh hhhh favv-^-hhvv -p .....

—’—7a-^-aa-’ o^uhiphcatis omnibus pc*

aa, aedivifisper faöaque tranfpofitione cogniti

mini, erit nbsp;nbsp;nbsp;30 t''t'—hh nbsp;nbsp;nbsp;nbsp;. Dein reftituds

ja bb nbsp;nbsp;nbsp;Ja bb

x h loco V, nbsp;nbsp;nbsp;loco 1 fe,atquejr ~ c loco ipfius z.»

expunftisque quae fe invicem deftruunt ac omnibus rite ordina-tis, ÜQtjfy nbsp;nbsp;nbsp; a cy X -^cx-^-dd. Quod determi'

nandum, demonftrandumque erat.

-ocr page 317-

L I B. II. C a p. III.

%h%y

hy X

Sisquatiofit x x•\-^ aj‘:Xi ,aut xx

-a ajZDo.

hy * nbsp;nbsp;nbsp;by

Aflumpto juxtaRegulam v COX— ~, ent xCXD’Z'H- ~,eoque fub-

'ftituto in locum ipfius x, ejufdemque quadrato loco x x, fublatif-1 n nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;^ hyy

lt;lueiisqu3Efeinvicemdcftruuntjent'z;'y—¦ ~~ i ayzoo. amp;,

faöa congrua tranfpofitionc, wZO nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;eft,multi-

plicatis omnibus squationis terminis perv? a, produftoque divifo

• Dein, aflumpto nbsp;nbsp;nbsp;j habe-

biturj 00^: ^^, eoque fubftituto in squatione loco ipfiusj, at-

. r nbsp;nbsp;nbsp;11nbsp;nbsp;nbsp;nbsp;• aa^ivnbsp;nbsp;nbsp;nbsp;a® rnbsp;nbsp;nbsp;nbsp;of

queiplms quaaratolocoj^,ent~^y- nbsp;nbsp;nbsp;, Iive^s, — ^

Quiquidem cafuseft Theoreraatis 13'“, acproinde

Locus quïfituserlt Hyperbola.

Ad cujus itaque peculiarem determinationem efto in appofita figiira ipfius x initium immutabile A punftum, eaderaque x in li-neaAB ab A versus B indefinite fefeextendcre intclligatur, fit-que angulus,quem x amp; j comprehendunt, sequalis angulo A B E.nbsp;Deinde, quoniam ex antediftis facile colligitur Hyperbolam hoenbsp;cafu amp; fimilibusitaefl'edefcribendam, utordinatim adejus dia-metrum applicatje fint ipfi A B ^quidiftantes, duöa refla A C ipfi

BE parallela, quoniam t/ 3D .v — ~ , ducenda porto eft redla

AM; ita ut omnium ipfi A B parallclarum partes, inter A C amp; A M interceptcE, veluti C M , ad partes ipftus A C inter A amp; di-öas parallelas interceptas, veluti A C, eandem rationem ha-beantj quse eft inter ^nbsp;nbsp;nbsp;nbsp;; hoe eft, ut fit quemadmodum ad

ha A C ad CM. Vndefi A C feu BE indefinitefumpta voce-

tur j,erit C M amp; fimiles 33 ^, ac dcfcribends Hyperboles diameter in dicta A M. Porró, quoniam 33j — ^ , fi ab A C au-

feratur A F 33 nbsp;nbsp;nbsp;: erit F C indefinite fumpta 33 a:, amp;, duEta F N

ipfi A B parallela, N centrum. Ac proinde, cum ratio diuftse N D ipfi F C jequidiftantis amp; ^qualis ad redam D M aliarumque fimi-lium fit cognita, nerape ut 4 ad é, fitque iüdem notus angulusnbsp;ParsILnbsp;nbsp;nbsp;nbsp;O onbsp;nbsp;nbsp;nbsp;N DM,

-ocr page 318-

ipo E L E M. C V R V A R V M NDM, fubiifdem comprehenfus, utpote squalls ckto velaf-fumpto angulo ABE, erit quoque ratio N D ad N M aliarutn-que fimilium nota, q^us fit ut a cognits ad e itidcm cognitatit*

Hinccum NIgt; feuF C indefinitefumptaexprimaturpcrs;, erit

NM itsdemindefinitefumptaoo ^ , cujus quidem quadratucft

cum juxta focmulam Reguls unum squationis terminum cori^ ftituere debeat, multiplicanda eft fuptafcripta squatio per etr

produdumque dividendum per lt;i4,itaut fiat

Quo perafto, fi juxtaRcgulam femi-latus tranfverfum fiat N ^

vel N H GO ^7^, ac ratio tranfverfi lateris ad reöum, ut r e ad b b

iifdemque lateribus %c diametro amp; centro jaminventis Hyperquot; bole defcribatur G E: dico curvam G E efle Locum quafitum-Sumpto enimin capunöo utcunque, velutiE, dudaqueE^nbsp;in angulo A BE, dato vel afliimpto squali, nec non E C ipfi A ^nbsp;parallela, fecantediametrum AMinM; fieademEB,.boc eft»

AC, voceturj,erit,utfupra,CMgo^, acproindeME, fi'^^

AB-—CMjGOs—hoc eft, v. Eftautem, utfuperiusannoquot;

tatum,N Moo ^, atque ex hypothefi N GFeu N H GD^ jideo-

quc HMgo^ ^'*, amp; MG GO ~—ac proinde redanquot;

guluifl

I

-ocr page 319-

Lib ïl. C AP III.

^gulum H M G X nbsp;nbsp;nbsp;cum ex natura Hyperboles

fitutlatosreftum adtranfverfam, fiveut^iiade^, itaMEqua-dratum, id eft, ad prsediftum reftangulura HHG: erit

¦lt; e V V nbsp;nbsp;nbsp;eezK f f

^ quot;F

faólocj^uepereedivifo, —^ hb

la)^ _ adeoque, multi-


^ 3Q —11—, amp;,raultiplicatis omnibus terminis per a a,

Xcc—Ö • Deinreftituto;—~


in locum ipfuist,exurget -j^ZOyy-


bh


plicatis omnibus per b b y faóloque divifo per lt;* nbsp;nbsp;nbsp;, habebitur

^ T, :3jihlL —.z ay. Deniquc reftituto a: — in locum ipfms Vy cxpundiscpie iis quse fe invicem deftruunt, atquc omnibus ritenbsp;ofdinatis,fietnbsp;nbsp;nbsp;nbsp;• Quodfuitpropofitum.

P R O B L E M A II.

‘Pro^qfitio \6.

Datis duobus punflis tertium invenite , a quo ad bina data duftx revise lineae dato dilFerant intervallo,nbsp;iocumque determinate ac defcribere, quern quaefitumnbsp;punftum contingat.

Sint data duo pun6ta A amp; B,oporteatque invenire tertium, ut-puta C, ita nempe ut dud* reds C A, C B diflerant dato intervallo F G feu A D.

Quoniam inqusftione angulus datus non eft, quo facilior fit operatioaflumatur redus, ideoque a pundo C in redam AB,nbsp;qus data punda conjungit, produdam, fi opus fuerit, intelliga-turdemiflaperpendicularis, utCEj turn, luppofitis,juxtaRe-gulam, A E amp; E C incognitis atque indeterminatis, aflumpturanbsp;angulum AEG comprebendcntibus, tanquam cognitis ac deter-jninatis, earum prior, nimirum AE, vocetur'a;, acpofterior,nbsp;nempe E C, nominetury, ipfa auteni A B, feu datorum pundo-rum cognita diftantia, vocctur a, amp; data? G five AD exprima-tur per b. Hinc cum B E five ( fi pundum B cadat inter A amp; E )nbsp;AE — A B, aut (fi pundum E inter A amp; B cadat) A B—A E fit

' nbsp;nbsp;nbsp;Oo inbsp;nbsp;nbsp;nbsp;CD.V

-ocr page 320-

Elem, Cvrtarvm

co x~a,8c A C CO)/ X x ‘yy,z.t^QzDy x x— z ax aa yji fitque A C — A D CO B C: éequatio erit '

YXX-^yyb ZO Yxx^ ax aa 77, faftaqueoperatio-ne convenienti, ututraque jequationis pars a figno radicalilibCquot; retur, amp; tranfpofiiis tranfponcndis, eritnbsp;4 b byyzo^a a x x—4 bbx x—4nbsp;nbsp;nbsp;nbsp;x ^ b b ax af'—z bbaa-^-b*'

Vndefada divifioneper ^aa — 4^^habebitur^^^ coa-at—

ax iaa — Deinde afl'iimpto;u%taRegulam v zox — erit x CO z' 4-|^, ideoque fubftitutohoc valore in locum ipfius.Vjnbsp;atque ejufderh quadrato locoxat, expundisque iisquasfeinving. I.


cemdeftruunt,erit Ja—hh ^ nbsp;nbsp;nbsp;Qi*'quidem cafuseft

Theorematis iz^'hujus libri , ac proinde Locus qusefitus erit Hyperbola. Cumquez/aflumptalicprox—dab A versusEnbsp;fumaturAHco^^j erit, juxtaRegulam, Hcentrum, amp;femi'nbsp;diameter tranfverfa (putaHGab una, amp; HF ab altera parte gt;)nbsp;CO )/ 5 ^ ^ j id eft, A ^ 5 ica ut diameter tranfverfa F G ( qute qu?-dem, obapplicatam C E ad diametrumHE perpendicularem»nbsp;tranfverfus quoque axis eft,) fitco Ratio autemtranfverfanbsp;diametri adparametrum, feu quadrati tranfverfte adquadratutnnbsp;fecundse diametri, eritut^^adlt;«^? — bb. Vndepereaquselibnnbsp;primi capitibus fecundo amp; ultimo expofita funt Hyperbolatnnbsp;ipfam delcribete baud difficile erit. Porrö cum quadratum ferni-^nbsp;nbsp;nbsp;nbsp;diame-

-ocr page 321-

Lib. U. Cap. III.

diametri tranfverfaefit GO ^ erit quadratum femi-fecundas dia-ïïietri ZD ~aa — nbsp;nbsp;nbsp;Atqui cum FB fiveB H H F fit 30|^

amp; BG fiveBH FIG 0O{^ —eritquoque reÖangulum P B G 00 5 «Ï a5^ k nempc 00 quadrato femi- fccunda? diametri,nbsp;five, utVeteresloquebantur, sequalequadrantifigure ad tranf-Verfum axem faöse: ideoque pundda A amp; B ea ipfa lunt, quse vul-go oppofitarum Fiyperbolarum Foci five Vmbilici nuncupantur.

Vnde apparet, ex prjemiffis redte inferri, qus fequuntur.

Corollarturn i .

Si ab afTumpto utcunque in Hyperbola pundlo ad u-trumque Vmbilicum reftie ducantur, earum major mi-norem longitudine tranfverfi axis fuperabit.

Etiamfi veritas prsecedentis Corollarii ex antedidtis omnino conftet, cum tarnen illuda Veteribus, Recentioribufve, quodnbsp;fciam, nonnifiper multas ambages longaquedifficiliumTheo-rematum concatenatione hadlenus demonftratum fit: id ipfumnbsp;hic demonftratione unica, amp; quidcm. breviore fatisquc fimplici,nbsp;aliter oftendilTe non inutile forte judicabitur.

' Efto igitur Hyperbola qujelibet G C, cujus centrum H , tranf-verfus axis FG, atqueVmbilici A amp; B, adeoque reöangulum F B G ut amp; G A F femi-fecundae diametri' quadrato tequale. Du-ftisautem abaflumpto qiiolibetcurvcE pundoCad punda A amp;

B redis C A, C B, ordinatim ad axem applicetur C E, fiatque ut HF ad FI A, itaHEadHM, ideoque AHE redangulonbsp;quale redangulumFHM. Vnde cum fit *,utnbsp;nbsp;nbsp;nbsp;per wfri-

H F ^ ad G A F, ita F E G ad C E f: erit quoque, per eompof. ra- TpaT tionis contrariam, utnbsp;nbsp;nbsp;nbsp;fecundi.

HF^ad (HF^ GAF,ideft5,ad)HA^;itaFEGadFEG‘‘™quot;’^'‘^

C E yj adeoqueut nbsp;nbsp;nbsp;ut una

HF^adHA^, ita(HF5- FEGfive') HE5’ ad H A'a ^^01 F E G C E Eft autem quoque ®, utnbsp;nbsp;nbsp;nbsp;ad unai»

H F^adH A^'jitaHE^adHMiy. Quocirca nbsp;nbsp;nbsp;7nbsp;nbsp;nbsp;nbsp;confeq,,

H M^OOH A ^ F E G C E hoc eft,addito utrinque H F ^ mnesan-feu H G ^, erit nbsp;nbsp;nbsp;tecedeir-

O o j nbsp;nbsp;nbsp;HiVi

, , , r V t n^' nbsp;nbsp;nbsp;omnes

•confeq. per IX nbsp;nbsp;nbsp;’ffr OJemdt, ^ excanjtruclimamp;pemfexii. 7 per Oquot; 11 ^uinu^

-ocr page 322-

^94 nbsp;nbsp;nbsp;E L E M. Cv R^V A R V M

' t fer 6 pcundi.

rHF^ rHA^

HM5' lt; feu 30“) feu (H F j F E G,i.e.')H E^'j C E f-CHGf CHBf

Hincadditisvel fublatis ab utraque squationis partezqaalibiis*

rFHM nbsp;nbsp;nbsp;cAHE .. , ,

i fer 4 fscmdi.nbsp;i per 47nbsp;primi.nbsp;4per 7nbsp;fecundi.nbsp;i per ^7nbsp;frimi.

nitmrums leu bisabuna,amp;lt; leu nbsp;nbsp;nbsp;. ,nbsp;nbsp;nbsp;nbsp;^

CGHM nbsp;nbsp;nbsp;CBHE ®

FM^C3{AE^4-CE^,ideft ^) ACg'; itcmque ** GM^'OOCBE^ CE^jideft^) BCq. Cumqueproptereanbsp;F M fit 30 A C j amp; G M CD B C j fitque ipfarum F M amp; G M dif*nbsp;fercBtiaF G, manifeftum eft ipfarum quoque A C amp; B C majo-*nbsp;rem fuperarc minorem, ejufdem F G, nempe axis tranfverfijlonquot;nbsp;gitudine. Qpoddemonftrandum erat.

doroilarium i.

Duftis a qnolibet Hyperbolae putKffo ad utrumquc Vmbilicum retftis , quae angulum iis comprehenfuninbsp;bifariam dividit linea curvam in eodem pun6lo con-tingit; amp; converfim.

Si enim qux angulum A C B bifariam dividit redla I C K noii continual Hyperbolamin C pundo, fecet eandem, fi fieri poteft»

Fig. I,


atque ita faltcm aliquo fui puiido,Ycluti K, intra Hyperbolam

-ocr page 323-

Lib. ir. Cap. 11.

TTum duSis K B, K D, amp; K A (quarum pofterior Hyperbolam fecetin L, aquo adBduöa fitBL), cumin triangulisD CK,nbsp;S C Klatera DC, C K iateribus B C, C K utrumqueutrique,

pig. J I.

• Cume^

nim ex

hypothe-i

li anguli

AGI8c

BCI®^

quales

ponan-

tur.erunt

quoque

anguli

ACK 8C

BCK,

quiipfis

iunt

deinceps, per ijnbsp;primi ^nbsp;quale«.

circa * aequales angulos, sequalia fint, erit quoque bafis D K ba-fiBKacqualis. Gumquc porro, juxta Corollarium praecedens, A L ipfam LB, ideoque amp; A K redlas B L, L K, fimulfumptas,nbsp;fuperetintervalloADj fitqueBK, ideoque amp; KD, ipfisBL,nbsp;L K fimul fumptis minor: per confcquens A K eandem K D ma-jorilongitudinequamcftADexcedet, ideft, ipfaAK binisre-Fig. IIL

3gt;;

Af

1 lt;r B

0isKD,DA fimul fumptis major erit. Quod cum abfurdifli-mum fit *, non fecat Hyperbolam rcda IC K, fed eandem con- * ftt lo tingit in G punóto. Gumque nonpoffit in eodem punfto G aliai”^^*

reda.

-ocr page 324-

7.^6 ElEM. CVRVARVM

« pff 5 reétaHyperbolam contingere quafnl C K', manifeftumeftcon-*

Corol. 6 verfim, cam, quae Hyperbolam in C contingit,angulum quoquc frmihu- ^g q bitariam dividere.

Exem^lum redtiBionis aquationufn adformulam Theorematis XIV.

Si squatio (\tyy nbsp;nbsp;nbsp;— z co—’ xx d X kE» afllitn-'

ptojuxtaRegulamxecO/'—— , hoceft, yCXDz c

coque fubftituto in locum ipfiusj, ejufdemque quadrato loco^ƒgt;

fublatisque iis,qu3e fe invicem deftruunt,erits: —

— ccOO~~xx dx /^i^. ideft,faftadecent!tranfpofitione« .nbsp;nbsp;nbsp;nbsp;hbxx ,nbsp;nbsp;nbsp;nbsp;2. b c Xnbsp;nbsp;nbsp;nbsp;1 1 r

cnts,?:CO—XX --\-dx—~- c c

aa nbsp;nbsp;nbsp;a

¦—aaxx-i-bbxx . dax—xbcx nbsp;nbsp;nbsp;, i r c r

zzOO-- H--T---Suppofito au-*

tem 4majorequam^ , ac multiplicatis omnibus aequationis tef' minis per a a, produdtoque divifo per a ah b,nx. quantitas x X

ablque fradione invcniatur,erit-^7 co—xx -j-,--

A nbsp;nbsp;nbsp;dd-^obnbsp;nbsp;nbsp;nbsp;dd'—hb

^ cc acL ^ nbsp;nbsp;nbsp;lam verófifaciliorisoperationis gratia loco

aa^i


~ a ab b düd'— z bacnbsp;£t Hb bnbsp;ccaa-^nbsp;nbsp;nbsp;nbsp;a

a abb


fubftituatur 2/a: eritsquatio----—xx zhx

¦* nbsp;nbsp;nbsp;aabb


, aut


aazK


-{¦XX ¦—2 hxZD


¦kXa.a


^-r-.v--“ nbsp;nbsp;nbsp;aa — bb

Hinc fijuxtaRegulamaffumatur t/X-v—h (iveArX't' ^jatqu^

hoe inlocumipfmsar, ejusquc quadratum loco xx lubftituatur, ac expungantur qiiae fe invicem deftruunt, habebitur

•{¦vvhhzo nbsp;nbsp;nbsp;decent!tranfpofitio'

ne , erit nbsp;nbsp;nbsp;•jyvv-{-hh-{-.. Atqueitaapp*'

ret aequationem efferedudam adformulam TheorematisXd v, ideoque Locum quïfitum aut Ellipfin aut Circuli circumferenquot;nbsp;dam exiftere. Rurfus verb facilioris operationis ergo loco

rfcribatur- , amp;Ioco^^ nbsp;nbsp;nbsp;fcribatur//,


-ocr page 325-

L I II. A P. 111. nbsp;nbsp;nbsp;1^7

Ad peculiarem autem prccdiöi Loei determinationern ac de-fcriptionem efto in appofita figura ipfius initium immutabite A pundum, atque eadem x fe in linca A E ab A versus E indefinitenbsp;extendere intelligatur, fitque angulus datus vel affurnptus, quemnbsp;yamp;cx comprehenduntjSqualis angulo E A K vel cjufdem ad duos

redoscomplemcnto. Hincquoniam j:C)0ƒ—^ nbsp;nbsp;nbsp;fiupra

IlneamAE exfu'rgere intelligatur,dflcenda quoque eft fupra ipfani redaKL eidemparallela, ka ut pars redae A K onaniumque ipfinbsp;sequidiftantium inter prasdidas A E amp; K L intercepta,yeluti A K,


EL amp;c squeturecognits*. ac deinde per pundum K infrare-dam KL ducenda eft reda KB in tali angulo, utredarum o-mniumipfi A K parallelafumpartes quainter KL amp; KB inter-cipiuntur (veluüLB) ad partes ipfius KL, inter eafdemparal-Idas amp; pundum K interceptas (ut verbi gratia L K ) eandem ha-beant rationem, quas eft inter é» amp; lt;«, hoe eft, ut fit uti 4 ad b, ita K L ad LB. Atque ita pofita KL fiveAE, indefinitefumpta,nbsp;eXjAT, LB omnesque ipfi parallels inter KL amp; KB intercepts

èrunt —. Vnde ex prsdidis conftat diametrum fore in redaK B,

Pm II.


Pp


ad



-ocr page 326-

298 Elem. Cvrvarvm ad quam ordinatitn applicata: fint ipfi A K xquidiftantes-Iam veronbsp;cum fit CO AT — /?, a reda K L five A E auferenda eft K H, ita utnbsp;eadetn KH fit CD^i ideoque HL indefinite quoque fumpta Cïgt;nbsp;Xh[cav. Deinde pcrpundum H ducendaeftHG ipnnbsp;parallela, fecans inventam diametruminG, eritqueidemintct'nbsp;Icdionis pundum G qusefitac Ellipfeos centrum. Porró quoniamnbsp;fimiIiumtriangulorumKHGamp; KLBnotaeftratio laterisK Hnbsp;ad HG live KLadLB, utamp; angulusfubiifdem latcribuscon»nbsp;tentus, utpote sequalis angulo dato vel affumpto E A K, erit quo'nbsp;que nota ratio lateris K H ad latus K G five K L ad K B, qu£E pO-natur ut a cognitas ad e itidem cognitam. Ideoque cum H L fivCnbsp;GM, quaeipfi HL parallela intelligitur , indeterminate fumptanbsp;fit CD t' gt; erit G B, fimiliter indeterminate fumpta, hoe eft, quseli''nbsp;betdiametri portio inter centiumamp; quamlibet ordinatimappliquot;

catam intercepta, CD —• Cujus quidem interceptae quadratutrt

cum in formula Theorematis XIV ultimumsquationistermtquot; num conftituat, aequatiofupraexpofito modoitareducatur, ut

terminus ejusextremus fiat idquod fadumerit, fi finguü

xquationis termini multiplicentur per pjrodudumque dr vidatur per a a. inde enim fequenti modo fe habebit aequatio'

. ,Hinc fi juxta Regulamfemi-latus tranfquot;

verfum G F velG C fiat x nbsp;nbsp;nbsp;1 eft, amp; ratiotraufver*

fi lateris C F adredumlatusFN, ut/ee ad^lt;i4, iifddfhque laterF bus, acdiametro, centroque, modóinventis, Ellipfisdefcribaquot;nbsp;tur F D C, fecans fedam A E vel A K produdam in I: erit cutvanbsp;ID C Locus qujefitus.

Sumpto enim in ea pundo uteunque, veluti D, dudaque P ^ ipfi A K. parallela, ac fi opus fit produda utfecetredas KL^nbsp;KB in Lamp;B, fieadem D E vocctur v, erit DB, hoe eft,

igt;x nbsp;nbsp;nbsp;^

E L L B ZDy — t- ~ feu 2:.. Eft autem ut jam annotatu»* eft G Bx atque ex conftrudione G F vel G C X ^,ideoqucnbsp;FBx-^ ^jamp;B Cx^ — ac redangulum F BCx

. Hiac cum ex natura Ellipfis fit ut N F ad F C, hoc eft»

Ut

-ocr page 327-

Lib II. Cap III. nbsp;nbsp;nbsp;199

/ff, itaD Bquadratum,hoc eft, s:adpr£edilt;ftum re-

«aangulum F B C j erit 20 nbsp;nbsp;nbsp;, id eft, multiplica-

tis omnibus per a a, acdivifis per eey erit

~ OO/y—Wjideo-

que reftituto x '—h loco V , atque

ccaa-^kkaa . nbsp;nbsp;nbsp;,



locoi

Z *

ZOhh-^

——-j-— ^xx

aO’^^bh

ihxhhy hoc eft, aazKnbsp;nbsp;nbsp;nbsp;,

c c a aa


aa


aa-bb


(I a ^

— . Por-


loco t L


aaxz

aTHTb X X

’—daax-^ xbeax aa——bb ~nbsp;nbsp;nbsp;nbsp;20


id eft, fadamultiplicationeper aa--bb aedivi-

^ A ' o b


fione per lt;* lt;*, erit 5, x: a; .j; ¦


bbxx


•d X-


ibex


CO c c


quot;1


Ac denique loco z. fada reftitutione ipftusj» — c deletisquc iisqux feinvicem tollunt, ac omnibus rite ordinatis, obtinebi-tur77 nbsp;nbsp;nbsp;nbsp;— z cjfo:) — XX dx kk: Quoddetermi-

nandum ac demonftratidum erat.

Notandum porro hie eft, quod ft angulus A K B forct redus, ‘ ac proindeordinatim applicats, utD B, K I, amp;c. ad diametrumnbsp;K B perpendiculares, ac fimul F N sequalis F C, prjedidam curiamfore Girculum, quemadmqdiina ex eleraemis perfpicuum eft.

Pp a ^ Pro-

-ocr page 328-

Elem. CvRVAB-YM Problema III.

Tropojitio 17.-

Datis duobus pundlis tertium invenire, a quo ad bi-na data duélae reftae lineae fimul fumptas datae longitu-dini aequales fint; locumque determinate ac defcnbere ^ qiiem quaefitumpunftum contingat.

Sint data duo pundla A amp; B , oporteatque invenire tertium, utputa C; ita nempe, ut duéls reftae C A , C B fimul fumpt^ïnbsp;aequales fint datx reóts line* D.

Quoniam in quseftione angulus datus non eft , quo facilior fit operatio, aflumatur reöus ; ideoque a pundo C in redamnbsp;A B, qu* data punda conjungit, produdam , fi opus fuerit,

Bg. I.

intclligatur demifla perpendicularis, nt CE. Tumfiippofitis» juxta Regulam , A E amp; E C incognitis atque indeterminatisnbsp;aflumptum angulum redum A E C coraprehendentibus tan-quam cognitis ac determinatis, earum prior, nimirum A E , vo^nbsp;cetur Xy ac pofterior, nempe EC, nomineturj; ipfa autemnbsp;A Bfeu datorumpundorumdiftantiacognitaappelletur^ï, amp; da'nbsp;ta D exprimatur per A Hinccum BE five (fipundumE cada.tnbsp;inter A amp; B )*A B — A E, aut (fipundum B inter A amp; E cadat)nbsp;AE — ABfit304~A;; atque AC30 ^xx-^yy ; amp; C B CX)nbsp;y'44•—•zax-\-xx-^yy ; 'fitqueD — A COOCB:zquatiocrit ,

h—XX yy zoVaazax xx 77 fadaque operation

nc

-ocr page 329-

L I B. Il’ t A P. III.

Be decent!, ututraqucasqulfconispars a lïgno radicalilibcretiir, amp; tranfpofitistranfponendis, erit

4 XX^aaxx—^4.v 4lt;ï^.vC0b baa a*-^bbjj,

hoe eft,fa(5iadivifioneper4/gt;^—44^», erit

XXax-3D\bb^aa—¦ nbsp;nbsp;nbsp;44- Afiumptodeinde justaRc-

gulamz/CXJAr—^a, eritx 30 nbsp;nbsp;nbsp; e%uefubftituta in locum

ipfi-USA:, ejufdemque quadrato locojex, expunöisque iisqux fc

jOl

h hyy

, five

invicem deftruunt: erit x xOD\bb-

znibb

bb—au’--

’~~xx. Qui quidem cafus eft Theorematis 13'“, aeproinde Locus qusefitus Ellipfis. Cumque v aflumpta Gt pro x — ^ , fi ab A versus E fumatur AH co jlt;*: erit, juxtaRegulam, H centrum,nbsp;amp;femi-diameter tranfverla (velutHFabuna, amp;HGabakcranbsp;parte) ZO {b-, ita ut diameter tranfverfa F G (quae quidem, obnbsp;applicatam C E ad eandem perpendicularem, tranfverfus quoquenbsp;axis eft,) fit X b. Ratio autem tranfverfse diametri adparame-trurn j feu quadrati tranfverfdC ad quadratum fecundae diametrinbsp;erit,utad^^ — aa. Vndeperea, quse Capitibustertio amp; ultimo libri primi expofita funt, quazfita Ellipfis facilliinè dcfcribe-tur. Porrö cum quadratum femi-diametri tranfverfe fit x 5 ^nbsp;erit quadratum femi-fecundx diametri zo^b b—i a a. Atqui cumnbsp;FBfeuG A fit Xnbsp;nbsp;nbsp;nbsp;amp; JSGfeu AF X \ b —nbsp;nbsp;nbsp;nbsp;erit quo

que reftangulum F B G lèu G hV ZO {bb—nempe sequalc quadrato femi-fecunda: diametri, five, utVeteres loquebantur,nbsp;squale quadranti figurse ad tranfverfum axem fadlse. Ideoquenbsp;pun(5laAamp; Beaipfafunt, quasvulgo Ellipfeos Foei five Vmbnnbsp;licinuncupantur. Vndeappare:,expr2miffisreöèinferri, quxnbsp;fequuntur.

Corollarium i.

Qu3e a quolibet inEllipfi punfto ad utmmqne Vm-bilicum reftx ducuntur , fimui fumptae tranfvcrfo axi sequales funt.

Quemadmodum autem in Flyperbola fuperiüs demopftra-tumeft, dudtarumCA, CB difterentiamtranfverfoaxiFG x-quari, itaamp; hic earum aggregatum eidem tranfverfo axixquale effe oftendetur, nempe, fi non per additionem amp; compofitionem.

Pp 3

-ocr page 330-

30^ El EM. CVRVARVM ut ibidem factum eft, fed per fubduitionem Sc divifionem argU'nbsp;mentacio inftituatur. Quod ipfum tarnen, adhibita nonnulla mu-tatione , elcgantius quoi^ue in hunc raodum abfolvi pofte vi-detur.

Efto quaslibet Ellipfis F CG, cujus centrum H, axis major FG, minor OP, atque Vmbilici A amp; B; adeoque rcftangU'nbsp;ium FBG ütamp;GAF aequale quadrato femi-fecundae diametr»nbsp;HO.

c.__^

w f nbsp;nbsp;nbsp;_ /nbsp;nbsp;nbsp;nbsp;*nbsp;nbsp;nbsp;nbsp;.

ÏÏ

? 1

* \ A JcA

a lt;i B J

V

Dudiisab aiTumpto quolibct curvatpundo C redis C A, C B, ordinatim ad utrumque axem applicentur CE,CN; amp;fiatu*^nbsp;H F ad H A , ita H E ad H M , adeo ut ' A H E redangulonbsp;jequalc fit reólangulum FHM j fumaturque H Q^aequalis ip^nbsp;H E. Hinc cum fit ^ ut H F ^ ad H A ^, ita H E 5' ad H M 5', er'*”nbsp;quoquepcrconverfionemrationisutHF^adG A Ffeunbsp;id eftutCN^ fiveHE ^adON P , ita idem H E ^ ad E M 0.»nbsp;ac proinde ^ squalia fiintredangula O N P amp; E MQ. Quocirquot;nbsp;cacum ® H M^unacumE MQ, id eft, cumO NP redangulo»nbsp;xquale fit H E ,5' ; fitque amp; H F ^ ^ asquale quadratis redaquot;nbsp;rum H A amp; (HO ® feu CE una cum redangulo ONP*nbsp;eruntHM^ ONP HF^ aequalia HE^ HA^ CE^

ON P. AcproiudefiutrinqueauferaturONP redangulu'^» remanebunt bina quadrataredarum HM amp; HFfeuHGfin^*^^nbsp;sequalia tribus quadratis redarum HE, HA feu HB, amp;

-ocr page 331-

L I B. IT. Ca p. III. nbsp;nbsp;nbsp;503

Hinc additis ablatifvè ab utraque aïquationis parte JEqüalibus, nimirum F H M feu G H M bis ab una,amp; A H E feu B H E bis abnbsp;altera parte: erit ‘ F M ^ jequale (AE^’ CE^', ideft% )AC^:'nbsp;nbsp;nbsp;nbsp;,7

itemque ^ G M 5’ squale ( B E g» C E g-, id ell ) B C Cum-que propterea refta F M aequctur ipfi A C , amp; G M ipfi B G; eritprfw/. ipfarutn A C amp; B C aggregatum tranfverfo axi F G squale. 4nbsp;^od demonftrandum erat.

_ nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;pr/wi;

Corollarium 2. nbsp;nbsp;nbsp;.

Duélis a quolibet Ellipfeos punfto ad utrumque Vmbüicum reiflis, fiper idem illud punélum altera re-pnbsp;agatur xquales cum utraque dufta angulos con-llituens, eadem curvam in dilt;flo pun^lo contingit; amp;nbsp;contra.

Si cnimrefta ICK itaduöa, ut stquales fint anguli ACI,

BC K, non contingat Ellipfinin C punfto , fecet candem, fi fieri poteft, in C amp; K. Deinde produöa A C ad L,i£a ut tota A L

I.

..„Ji

A. £

axi F G, ideoque * adjcfta CX ipfi C B asqualis fit , jungan-i pfrCe-turAK, BK, LK. Cum igitur, in triangulis LCK, BCKquot;/-! hu--latera L C, C K lateribus B C, C K, utrumque utrique, , circa^***' aequales angulos, sequaKa fint, erit quoque bafis LKbafi BKnbsp;xqualis. At vcrócum punftum KinEllipfilupponatur, erunt,

per

-ocr page 332-

C A P V T I V.

ReguU rniverfalis in^eniendi ac deter min andi loca quMihetflana 0'’ folida.

lam veró his omnibus ica prxmiflis , pro general Regula concludi poteft, aequationes omnes , quaeinbvnbsp;dagatione Locorum prasdi^lo modo obvenire atqu^nbsp;¦ obtingere pofTunt, ita ut in iis neutra qüantitatum in-cognitarum in fe dufta, neque faftum fub iifdem ad fo-

lidum

-ocr page 333-

LibII. CapIV. nbsp;nbsp;nbsp;30y

Udum excurrat, fed aur quadratum, aut planum non excedat , ex aliqua fequentium formularum conftare,

Vel ad earundem aliquam Mediodö jam explicate re-duci pofle: nimirum,

y 30 —, five,quodidem efl;,jV co x\ cum fupponi

“ poffiteffe^oo^. nbsp;nbsp;nbsp;gj:?

jy CO ^ 8 CySely co r — —. nbsp;nbsp;nbsp;.

Sed hfc notandum, fieri etiam poflè, ut per opera-tionem quantitatum incognitarum altera evanefcat, alteraque fola notae alicui quantitati aequalis remaneac,nbsp;ficut fuperiüs expofitum eft.

'yy 00 ^A:,autconverfimlt;^jy a:gt; xx. yy'j:» d x. ff, aut converfim dy. ff cox x.nbsp;j zz co dx, aut converfim dy co vv.

1^2525 co d xff aut converfim dy.ff co w.

ZZCD^y^.ff

yya^'kff

[zzco^yy.ff

ngt;


y xcoff zxcoffnbsp;yvcoffnbsp;zvcoff

Supponendo ubiquejv amp; « ^antitates indetet-minam ac primo conceptasi at vero ^ clTe quanfra-tem affumptam, amp;quï compoCtafit exjy 8 aha qua-dam quantitate , vel in totnm cogniti, vel cui etiam altera incognita primüm concepta, nimirum Jf, permi-xta fit ; atque v quidem affumptam quoque efte, fednbsp;eo cafu conftare folummodo ex x R alia quantitatenbsp;cognit^, abfque ulla ipfiusy incognitas quantitatisper-mixtione: aut contra “i; effe co R aliaquyamquan-TarslLnbsp;nbsp;nbsp;nbsp;Qü

-ocr page 334-

300 Elem. Cvrvarvm

titate, cui amp; jy incognita per mixta elTe poiTit atque eo

quidem cafu^s exjy B alia quantitate in totum cognita

conftare.

Et ü jequatio fimilis fit alicui formularum fubN°i. comprehenfarum , erit Locus quaefitus Linea Refta;nbsp;fub N° X. Parabola; amp; fub N° 3. fecundüm fignorümnbsp;angulorumque varietatem vel Hyperbola, vel Ellipfis,nbsp;vel Circulus.

Vt autem praedifla Loca fpecificè determinentur five praedi-ftsLinexin plano Geometricèdefcribantur , fciendumett, ali-quod debere prafiipponi pundum, utamp; aliquam lineamaquo-exordium furaat, amp; per quam indefinite fe extendere intelliga-tur altera incognitarum quantitacum primo conceptarum ; item-que angulum quendam efle praEfupponendum, quem did* quantitates incognitte conftitiiantinpundo, inquolibi invicemjun-Ö£E intelliguntur.

Sit itaque in appofita figura, ut amp; in fequentibus omnibus, prardidum pundum A , didaque linea A B, a quo, amp; per quamnbsp;quantitas a; fe indefinite extendere concipiatur; atque angulusnbsp;A B E, quem faciunt quantitatesj amp; a;, in pundo B fibi invicemnbsp;jundge.

Et primo quidem cafu, cumLocus quatfitus cftLinea reda, nimirum, jequatione exiftente^COArvel/30 ipfum A pundum eritinitiumdidslinecE, atque ut eadem fpecificè defcriba-turfumendum eft in linea A B pundum utcunque, exempli gratia, B, ac per illud duda reda, velut H B E ƒita ut angulus A B Enbsp;prsefuppolito vel concepto angulo fit jcqualis, fi in eadem redanbsp;fumatur pundum , veluti D; ita ut A B amp; B D fint atquales, velnbsp;ut A B fit ad B D , ficut lt;« ad ^, atque ex A per pundum D duca-tur reda AD : erit eadem AD indefinite extenfa Locus qutefi-tus. At fi in tequatione inveniatur quoqueterminus e, ac ipfe quidem figno affedus fit, ducenda eft èpundo A ad eandem partem linese AB quam eft pundum E, autfifigno —adficiaturabnbsp;altera parte, reda A F ipfi FI B E parallela atque sequalis c cogni-tSE; dudaque F E vel F G, qus redam A B fecet in O, ipfi A Dnbsp;parallela: erit FE velO G indefiniteprodudaLocus quasfitus.

Sed


-ocr page 335-

Lib. II. C A p. IV, nbsp;nbsp;nbsp;307

hx . nbsp;nbsp;nbsp;•

Sed fi seqif^ttio Citj ODc-—~ , in dida linea H B E funji^ndtim eft

ptumeftpunaomH, dacendaeftFI ipCAHparillela: eritqup eato Ï1 produaadoncc cumliMa AB comctdatLocusquic-

‘‘‘“Eteoim, cumtamAB ciutaBOfit;»*, autABadBDab

una ut amp; AB ad BH abalteraparte, fitut^ad^j acproinde

B D vel B H CO nbsp;nbsp;nbsp;cum A F feu D E vel D G ut amp; HI

fmt squalcs c cognits: erit BEfiveBD DEco^ e,amp;BG

fiveBD—DGcO^--‘^gt;acBIfiveHI—HBcOe—^\Vn-decumpundumBfumptum fitutcunque, eademerit de omnibus aliis, in linea AB, prsdidifve locis, aflumptispundisde-monftratiot atqueita patetprsdidaslineas AD, F^, FG, amp; FïefleLocaqusfita, Quod determinandum, demonftrandum-

Squot;'”'-- nbsp;nbsp;nbsp;Cl.,dnbsp;nbsp;nbsp;nbsp;At

-ocr page 336-

3o8 Elem. Cvrvarvm

At veto fi juxta formulas fub N*’. z exhibitas Loens qusfitus fitlinea Parabolica, erit

I. Primo cafu, quandoaequatioeftj^ 00 nbsp;nbsp;nbsp;ipfa A B Parabolae

diameter, ad quam ordinatim applicatae faciant angulos, dato vel aflumpto angulo A BE tequales, atque ejufdem vertexnbsp;A punótum.

F'

Aic

11. Secundo cafu pofita xquatione^j^ OO d x.ff, manente diametro in eadem linea A B, furaptaque, ut m fequenti figura,

AF O0^gt; erit ejufdem vertex in puneSo F. Quodquidem

punélum F, fi uterque terminus tam a! at quam ff figno fit affeftus, ab altera parte punfti A, qua eft punélum B, fumen-dum eft; fed fi vel terminus d x, vel terminus /Zquot; figno — affe-«Susfit, ab eadem partepunéli A, quaeft punftumB, fuminbsp;debet: 8c quidera fi terminus d x figno-Haftcétns fit, ab Anbsp;versus f Parabola defcribenda eft; fin contra terminus dxnbsp;figno — affeftusfuerit, incontrariampartem, ab F nempenbsp;versus A, defcribi debet.

...... ¦ ' nbsp;nbsp;nbsp;At

-ocr page 337-

Lib. II. Cap. IV. nbsp;nbsp;nbsp;309

Ktüxfyi^üodtz.z.'X) dx ^yQ\z.z.ZD d xff, cum?, non fit quantitas primo conceptafed affumpta, velaffumptaeritpro

j ^ c, velpro;- ^ , vel deniquepro j nbsp;nbsp;nbsp;— 8 f.

III. Etfiquidem?:aflumptafitproj 8 ^^jquifitcafustertius,du-cenda eft per pundum A reda A D jpfi B E parallela atquenbsp;CDc; itaut, fi?, affumpta fit proj'—c, pundum Dcadatadnbsp;eandem partem lineae A B , quam conceptus eft angulusnbsp;ABE: Et, fi?.fitaffumptapro^ c, pundum D econtranbsp;ad alteram partem linea: ABcadat. Deinde dudaD K ipfinbsp;A B parallela, eritin eadem D K Para5ola2 diameter, amp; Dnbsp;vertex, fi xquatio fit ?, ?, go .v.

IV. nbsp;nbsp;nbsp;Sedfifit?,?,G0^3^A:. ƒƒ, quifitquartuscafiis,fumptaD L GO

erit vertex pundum Ljquod quidem pro terminorum d x

amp; ff per vel — affedione eodem modo , ut fupra de pun-do F didumeft, velcitravel ultra D pundum cadet; utiamp; vel inhanc vel in illam partem , prout terminus lt;5/a; figno- -vel — adfedus fuerit, ipfa Parabola, ut fupra notatumeft,nbsp;defcribi debet: eritque omnibus amp; fingulis prsedidis qua-tuor cafibus Parameter GO d.

b X .

• V. Sivero?,affumptafitproj 8 —gt; quicafus fit quintus, fum-

pto in linea B E pundo M, ita ut fit A B ad B M , ficut 4 ad (quod quidem pundum M fumendumeftab eadem parte lines A B, qua conceptus eft angulus A B E,fi habeatur —nbsp;nbsp;nbsp;nbsp;^

b X nbsp;nbsp;nbsp;^

fed ab altera parte, fi habeatur ~ ) ducenda eft per

punda A amp; M reda A M: eritque A M eo cafu Parabols diameter, ad quam ordinatim applicatsfaciantangulos an-gulo A ME squales, amp; fi in squatione terminus//deficiatnbsp;aut nullus fit, erit vertex in pundo A.

V E Sin minus,qui fit cafus fextus, dudis per punda F amp; L redis L F L, qus interfecent fupra didas diametros A M vel iis innbsp;diredum adjundas inpundisN: erit vertex in N , velcitra,nbsp;vel ultra A pundum cadens, prout termini d x amp;//in squa-tione vel figno vel figno — affedi fuerint; utiamp; velinnbsp;banc vel in illam partem ipfa Parabola pro varia termini dxnbsp;affedio ne, ut fupra notatum eft, defcribenda erit.

CLq 3 nbsp;nbsp;nbsp;Si

-ocr page 338-

310

Elem. Cvrvarvm

Si denique 2:. afl’umpta fit pro ƒ 878 «¦, duöa,utmodo

cxpofitum fuit, A D GO c gt; ex pundo D (quod pro quantitatis c per fignum vel — afFedione, ut fupra, vel ab hac, vel abnbsp;illa partelineae AB fumi debet) ducenda cftredaD O ipfi

VILA M,qusE eft ad eandem partem,parallela, fi termini ~ amp; c

codem figno fint afFcdi, qui cafus fit feptimus.

VIII. At fidiverfo, qui fit cafus odavus, ducenda eft redaD P parallela ipfi A M, qus eft ab adverfa parte lines A B, atquenbsp;eadem D O veiP P fumendaeftpro diametro, adquamor-dinatim applicats faciantangulos angulo D O E velD P Enbsp;squales: eritque vertex pundum D ^ li terminus ff in squa-tione deficiat.

-gt;l

X)


Q.'


..io

IX. Sin minus, qui fit cafus nonus,erit idem vertex ipfarumD O velDP diametrorumamp; linearum LEL communisinterfe-dio, videlicet pundum Q, quodque iterum pro terminorumnbsp;dx 8c ff per fignum vel — affedione vel citra vel ultra Dnbsp;pundum caditj quemadmodum amp;ipfa Parabola vel versus

hanc

-ocr page 339-

Lib. II. Cap. IV. nbsp;nbsp;nbsp;311

hanc vel versus illam partem prodivcrfa termini « at aÖcétio-ne, utfupra eft notatum, delcribenda eft: Acpoftremisqui-dem iftis quinque cafibus jam explicatis Parameter crit ad d coguitam, ficut A B ad A M, hoc eft, erit ut A M ad A B, ita dnbsp;adParametrum.

Quorum quidem omnium demonftratio perfacilis eft. In-telligantur enim Parabola prsdidiis diametris ac parametris defcriptx, qua» per annotatos vertices tranfeant, fitqueordi-natim ad ealdem diametros applicatarum aliqua inredaOEnbsp;utcunque fumpta, amp; fupponatur eafdem Parabolas prxdidamnbsp;applicatam fecare in E pundto: amp; primo cafu, cum pars dia-metri A B inter verticem A amp; quamlibet ad eandem diame-trum applicatam intercepta, veluti AB, concipiatur, ut a',nbsp;ac fingulseillasapplicatjc, vity; fttqueParameter COd, atquenbsp;ex natura Parabolse ‘ reélangulum fub difta Parametro amp; re- ' fennbsp;I. (fta A B contentum fit go B E quadrato: crkdxü^jy,nbsp;nbsp;nbsp;nbsp;frimihu-.

Secundo cafu, ubi vertex eft in pundlo F cum triplici diftin-dtione, ut fupra monitum eft, notandum primo venit, in cafibus, ubi jequatio eft ƒ ƒ ZO dx 0 ƒƒ, pundum B in linea F B ab A versus B indefinite fumi pofte: cum iftis cafibus ab A versusnbsp;BParabolam defcribendam efle fupra annotatum fit; At verbnbsp;cafu, ubisequatioeft jjGO//—dxy cumjuxtaRegulamParabola in contrariam partem ab F versus A fitdefcribenda,nbsp;pundum B non nifi inter F amp; A aflumendum elle. id quodnbsp;etiam ex ipfa tequatione manifeftum eft. Quoniam enim innbsp;prsedida xquatione^jCO/T”— d x five quod idem eft ƒƒ—jjqqnbsp;dxy terminus/f majoreftquamlt;s!A:,utpoteeundemexcedensnbsp;quantitate idcirco quoque fi utrinque divifio fiat per dy,nbsp;majus erit quam v. Quare cum fecundumRegulam^^at-

queturredae AF, amp; arOOredaeAB, erit fimiliterreda AF major quam A B : ideoque B pundum inter A amp; F punda,nbsp;ficut didum eft, cadet, id quod ad cafus quoque lequentes ap-

plicatum efto. Porrb quoniam A F eft CO erit F B(hoc eft, obfervatatriplicidiftindione, utprsdidumeft, AB ^ AF,nbsp;atque etiam A F A B) squalls ^ R atque etiam — x\

eaque multi plicata per parametrum lt;/,fit redangulum dxf^ff,

atque

-ocr page 340-

5IZ Elem, Cvrvarvm

atque etiam ƒƒ—¦ d x. quod squale eft quadrate applicatte B E z. rivejj,acproindej^ ÖD dx ^ ff,atqueƒƒ zoff—dx.

Tertio cafu, ubi vertex eft in pundlo D, ac diameter in re-* (fta D K , quoniam A D feu B K eft CO c: erit K E, hoc eft,nbsp;BE — BKco/ — £¦; amp;KBE, hoceft,BEH-BKco/ f.nbsp;Cumqueeo caluicaflumptafitproj ^ CjCritKE amp; KBEcoc.nbsp;Eft autem D Kfeu A B CQ .v,parameterque zod, 8c reftangu-lum fub didia Parametro amp; redla D K contentum QO quadratonbsp;ex KE vclKBE. Quarecumhoc quadratumfrtCQ2;;e.,atqucnbsp;3. redtangulum illud zodx, erit z.z.Zodx.

Quarto cafu, ubi manente diametro in redla D K vertex eft

in pundlo L, quoniam DLfiveAFeft co^, eritLKfhoc eft, obfervata triplici diftindlione juxta Regulam, D K ^ D L,nbsp;atque etiam L D — D K ) sequalis xnbsp;nbsp;nbsp;nbsp;atque etiam— x.

qua multiplicata per Parametrum d, fit redlangulum dx^ff, atque etiamƒƒ— dx. quod aequale eft quadrato applicataf K Enbsp;vel K B E, hoc eft, c c: critque proinde zz,ZOdx ƒƒ atquenbsp;^.zzZOffdx.

Quinto cafu, ubi vertex eft in pundlo A , diameterque in redlaAM, cumfitut^ad^, itaAB, hoc eft, a:,adBM; eric

B M CO ^jideoque M E,hoc eft,B E—B Mco^— ~ nbsp;nbsp;nbsp;^

hx

hoc eft,BE BMc07-I-~ • Et quoniam eo cafu «^affumpta

eft pro ^ ^ —, erit M E amp; M B E CO ¦?.. At cum intriangulo

pfr 6 fexti.

ABM cognita fint amp; angulus A B M, amp; ratio laterum A B, B M, didtum angulum comprehendentium, nota quoque eft ‘nbsp;ratio reliquorum didli trianguli laterum ad invicem, atque innbsp;fpecie etiam lateris A B ad A M, quae fit ut a ad e. Ac proinde

cum fit ut a ad e,ita A B,h.e.,ar ad A Mrerit A Mco^ .Cumque porro juxta Regulam eo cafu fit ut A M ad A B, hoc eft, ut enbsp;ad a, ita (5^ ad Parametrum: erit Parameter co ^ . Qua multiplicata per AM feu ^ fiet redlangulum X a;. Quodxquale

eft quadrato applicatae M E vel M B E, hoc eft, a;, z:; ac proin-5. deeft?.;?, 30

.Sexto

-ocr page 341-

Lib. ÏI. Cap.. IV. nbsp;nbsp;nbsp;313

Sexto cafu , ubi vertex eft in piindo N, amp; diametA- in re-fta N M, quoniam eft ut A B ad A M, ita A F ad A N, hoc eft,

utvi ad If, ad AN : erit AN CO j amp; N M (hoc eft,

obfervata juxtaRegulatn triplicidiftinftione, A M (3 A N,

.atque etiam N A — AM)3equalis^ ^ ^, atque etiam

— nbsp;nbsp;nbsp;Qua multiplicata per Parametrum ~ , fit redlangii-

*\JS

\K

nV

KfV

\kquot;

lum dx ^ff, atque etiam ƒƒ— dx. Qiiod cum sequale fit quadrato applicatsE M E vel M B E , hoc eft , z z : eritnbsp;6.zzCOdx ƒƒ, atque j: ODffdx.

Septimo cafu, ubi vertex eft in punAo D, amp; diameter in rc-0:aD O, quoniam A D feuMi) eft 00 c, eritO E (fiveBE —

BM — MO)ooj — ^ OBE(fiveBE BM MO)

CO^ ^ c.Cumqueeo cafu cafl'umpta fit pro^ —

velproj' nbsp;nbsp;nbsp;OEamp;OBE oot.. Porro cumDO

Pm 11. nbsp;nbsp;nbsp;Rrnbsp;nbsp;nbsp;nbsp;feu

-ocr page 342-

314 Elem. Cvrvarvm

feu A\i fit 00 Parameterque feflionis OO erit reftangiir

lumfub Parametro amp;. redaD O contentum ZO dx. Cumque idem iUud reétangulum tequetur quadrato applicata: O E vel

7. nbsp;nbsp;nbsp;O B E , id eft,nbsp;nbsp;nbsp;nbsp;: erit ?, c 00 -v-

Odavocafu, ubi, manente vertice in punftoD', diameter

cft in re(5l:a D P, quoniam A D feu BKeftooe, amp; KPoo^, crit P E una (five BE — BK4-KP)0O y—£¦ ^ j amp; P E altera (fiveBE 4-BK — KP) ooj c—^.Cumqueeocafunbsp;«.affumptafitpro^q-^—cvelproj —nbsp;nbsp;nbsp;nbsp;attaque

PEoo^.Porró cumD Pfeii A Mfitoo — acParameter 00 —,

erit reftangulum fub Parametro amp; recta D P contentumO0lt;^ar. Cumqne idem reöangulum tequalcfit quadrato utriufqueap-

8. nbsp;nbsp;nbsp;plicatseP E,hoe eft, ^: erit quoquez.z.ZOdx.

Nono cafu, ubi vertex eft in punóto Qj amp; diameter in refta

Q_0 vel Q^P,quoniam,ut fupra,0 E eft 00/— ^ ‘— e, atque O B E0OJ ^ c; at vero P E una 00 /—c ^, ac P E altera 007 C— ^jfitqueeocafutLalTumptaproj ^ cxnbsp;erit O E, O B E, atque utraque P E 00 Et cum D O aut D Pnbsp;feu A M litOO^, atque D Q^feu A N ÖOnbsp;nbsp;nbsp;nbsp;erit Q^O vel Q^P

' (hoceft, obfervatajuxtaRegulamtriplicidiftindione, DO vel D P D Qj atque etiam QD —D O vel D P ) tequalis

~ nbsp;nbsp;nbsp;atque etiam ^VndefieademQ^O vel Q^P

multiplicetur perParametrum OO ^ , eritredangulutn ZO dx

ƒƒ, atque etiam ffdx. Quodquidem redangulum cum a:qiiale fit quadrato applicatas O E, O B E, aut utnufque P E,nbsp;p. hoe cft,tl?:: erit quoquedx ^ff,ntlt;]nez.z, ZOffdx.nbsp;Quat quidem omnia lunt, qua: hic demonftranda erant.

Quod autem ad sequationcs fuperioribus novem cafibus converfim correfpondentes fpedat, ut linca: Parabolicae de-fcribantur, qute fint Loca qusfita: pofitis iifdem, ut fupra, pernbsp;'nbsp;nbsp;nbsp;nbsp;pun-

-ocr page 343-

L I B. ÏI. C A P. IV. nbsp;nbsp;nbsp;31^

I.

puniSlum A ducenda eft reda A C ipfi B E paraftcla, ac deinde ipfa AC, ubique confidcranda, utconfideratafuitreda A B in fuperiori figura. Porro fumpto in eadem A C pundonbsp;lucunque, veluti C, atque per id duda reda ipft A B paralle-la, vclut O C E , erit iimiliter hsc O C E ubique conftde-randa, ficut confiderata fuit reda O B E in prscedenti figura,nbsp;nulla fcilicet alia mutatione adhibitL Exempli gratia: Siac-quatio fit CO AT x, erit A C diameter, A vertex, amp; Parame


ter CO d. Cum enim A C feu B È fit concepta utj-, amp; C E feu A B ut A,',redangulumque fub Parametro amp; A C contcntum,nbsp;hoc eft, dy, aequetur quadrato redas C E feu A B,hoc eft, x x:nbsp;erit, ut petitur, dyZDXx.

II. Sisquatiofitd/.//cOacA^jfumpta AF co j , eritF vertex,

manentc diametro in reda F C, atque Parametro colt;f- Eft

Rr a nbsp;nbsp;nbsp;enim

-ocr page 344-

316


enimprotriplicijuxta Rcgiilam diftinftioneF C CO/ B


ff.


ff

atqueetiam'^j —/: ac proinde rcdangulum fubParametro

ac eademF C contentum CO ö?/ R ƒƒgt; atqueetiam ffdy. Quod qiiidem reétangulum cum xquale litquadrato appli-catae C E, hoe eft, x x: eric, ut peütur, dy.ffzo x x.

I II. Si^equatio CO V, vel ^.y/co t't'j atque primüm alTumptafitprox e,fa6taADcoejfumptoquepunftoD abnbsp;A versus B, fiz'fit afl'umpta pro x c', at contra ab alteranbsp;parte, fi v aflumpta fuerit pro .v c, critjdudla D K ipfi A Cnbsp;parallela, diameter in refta D K. Etll terminus//’deficiat,

IV. nbsp;nbsp;nbsp;erit vertex in D; fin fecusinL, cumtriplici variatione, utnbsp;fupraexpofitumeft. Etpatet, D B five DAB, hoe eft, KE

five K C E fore v,D K C0/,atque L K cO/ R j^,atque etiam

^; ac proinde reÖangblum fub Parametro d diöaquc D K comprehenfumco^f/; at verb id quod fub amp; L K com-prehenditur O^dy R ƒ/’, atque ctumffdy. Quod quidemnbsp;reftangulum cumsequale fitaut fupponatur quadratoappli-catasKE flveK C E,hoc eftjt/x/: crit,atpetitur,lt;^/rcOx't',vel

dy.ffOD V V.

V. nbsp;nbsp;nbsp;STt deinde v affumpta pro x ^ ^,fumptoquc in linea O C Enbsp;punfto M a C versus E, fihabeatur— ^ j at ab altera parte

lincjeA C,lihabeatur nbsp;nbsp;nbsp;, ita utA C fitadCM, ficut^

' ad ó : erit in reda. A M diameter , ejusque vertex in

VI. pundo A,fiterminus//’deficiatj finminus, inN. Etpofita

rationeA C ad AM.ut^ade, aeproindereda AMco

a. d-

erit Parameter co ^ - Eft nbsp;nbsp;nbsp;C M CO ^ proinde

ME co./ — ^ , atqueMC E 00 / 4- ^ gt; id eft., ME vel

M C E 03 -z/. Quoniam ergo ex natura Paraboles redangulum fub dida Parametro amp; reCia A M contentum CO.quadrato exnbsp;M E velM C È, erit ,dyzo vv.

Porro cum N A fit x gt; erit N M x ^

etiam

-ocr page 345-

Lib. II. Cap. IV.

ctiam ^ — ~ : ideoque rcftangulum fub Parametro

amp; reda N M contentum COdji^ ^atque etiamff—dj. Quod quidem redangulum cum lit CD quadrate ex MEnbsp;vel MCE, hoc eA,vvi erit quoque dy.ffzo v v.

Vll VIII.pofitis iifdem qus fupra, diameter in D O, vel in D P; IX. amp;, fi terminusjj^ deficiat vertex in D; fin minus, in Q.nbsp;Etpofita rationeD KadD 0,ut amp; D K adD P, ficut

rameter CD — . Eftenim O E 33 x.---

4 ad ac proinde reftaD O, ut amp; D P cd ^; erit pa-a A ^ n , nbsp;nbsp;nbsp;/.AT---

-c, atquc

OCi

Rr 3

-ocr page 346-

3i8

Elem. Cvrvarvm

o C E 30.v4-^ rjitemqaeP E una coat— ^ -H-jacP E altera GO .V ^ —c, hoe cft, O E, O C Ê, amp; PE unavclaltera

a

erit DOz^.EftqueQO vel Q^P (ficutfupraNM}dd nbsp;nbsp;nbsp;, at-

dn

ffe € y

queetiam^ —proinde redangulum fubParametro amp;

' QP vel Q^P GO p ^ fff atque etiam ƒƒ — dy. Quirc cum idem reiflangulum squale fit quadrato ex O E vel O C E, aut ex unanbsp;altcravè P E, id eü'v v: erit quoque dj.ffoD v v.

Atque ita demonftratum eft generaliter, quod hoe loco propo-fitum fuit.

At fi denique jequatio fimilis fit alicui formularum fub N° ^ comprehenfarum , erit Locus quaefitus , fi terminus in quo iiivenitur xx \q\w figno fit afïè^lus.nbsp;Hyperbola; fin idem terminus figno — aflfedtus fit, El-lipfis: excepto tantum, cüm pofteriori cafuordinatimnbsp;ad diametrum applicatje cum ea reftos anguios fa-ciunt, amp; fimul tranfverfa diameter parametro eft x-qualis: quippeeo cafu, ut patet, quaefitus LocusCir-culus exiftit.

Et primo quidem cafu, cum nempe terminus in quo xvel-vv figno afïêdiis reperitur, ac proinde Locus qusfituseft Hyperbola, erit quoque terminusy/cum Ulo ab eadem squationis parte conftitutus vel figno afïeólus, vel contra; amp;fifigno —af-feflusfit, atque in xquationehabeaturfraöio , ipfa majoris per-fpicuitatis gratia in terminumj^ velt?, rejiciatur. Quo fado,nbsp;remanente utraque quantitate incognita primüm concepta, fe-

Cdfus quenti forma fe exhibébit squatio GD — .ff, ( id eft,

l'»“' ram nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;^

' nbsp;nbsp;nbsp;/xxnbsp;nbsp;nbsp;nbsp;‘yy

ffOD — )aut~ GOar.v—/f:eritque,utinfequentifigura.

cafu primo, nempe fi terminus ff cum termino in quo x x unam xquationis partem conftituens figno affeftus fit, diameter Hy-perboIsE defcribends in reda AX, quseduciturperpundum Anbsp;pofitione datte B E parallela. Sin contra, hoe eft, fi terminus ƒƒnbsp;iigno-—affedusfit, uti cafu fecundo, erit diameter in data pofi-

tione reda AB, qus indeterminate proarconcipitur; ita ut ad

eafdem


Ia.


-ocr page 347- -ocr page 348-

32.Ö Exem. Cye-varvm

hsereat fraöio, crunt latera tranfverfum Sc redum fibnnvicem xqualia. At vcró podtis /amp;cg in«qualibus,erit ratio latcris tranr-verdadreéliimut/ad^.nbsp;nbsp;nbsp;nbsp;•

Si enim defcripta intelligatur prsdida Hyperbob per pun-dum C in utraque diametro versus X amp; versus B refpedivè; fup-ponaturque candem fecare redam X E, quse duda dt ipd A B £e-quidiftans , ut amp; iplam B E ^ ad didas diametros refpedivè ordi-natim applicatas, in pundo E: erit

FXoD^q-/, nbsp;nbsp;nbsp;FBxr ƒ,

CXCDJ—ƒ, nbsp;nbsp;nbsp;CBooat—/;

ideoque rcdangulum FXCcojj—ƒƒ, amp; FBCrr)A;x—ff.

primi hu-

/HS

Cum autem latere redo ipd tranfverfo atquali exiftente rc-• per lo dangulum F X C • dt 00 quadrato ex X E feu A E, hoe eft, xar; ” itemqueredangulumF B C dt 00 quadrato ex BE, boc-eft,j_y :nbsp;eritj^—ff CO XX, hoceft, ƒƒ oo-vx-f-yyitemquenbsp;XX-ffcOyj’/dvejrjfO^xX'ff.

per 10

Sed cum fecus redo latere ipd tranfverfo jn£Equali exiftente unius ad alterum ratio fit, ut/ad^j fimiiiterque etiam ratio re-danguli F X C ad quadratum X E, aut redanguli F B C ad qua-dratum BE eadem fit*, qux tranfverd lateris adredum, Jiocnbsp;primi fc«-eft, eadem quje/ad^: erit ut/ad^, itaƒƒ—ffa.dxx; itemquenbsp;ut/ad^, itaxx—ffidyy, hoe eft, reduda proportionead ïe-qualitatem , erit 'lx xcjy gyjgff, ut amp;nbsp;nbsp;nbsp;nbsp;CO gx x—-^ff. unde

divids omnibus per^,fit 00 —ff, hoe eG:,yy 00 nbsp;nbsp;nbsp; ƒ/’»

ff. Quod demonftrandum erat.

At fi quantitatum incognitarum primo conceptarnm una ex arquatione fublata, ahaquein ejufdem locum jiixta Regulamaf-

Locusefl nbsp;nbsp;nbsp;^

Hyperbo- fumpta, ^quatio dt 00--\-ff (id eft, nbsp;nbsp;nbsp;—ff CO ), vel

g nbsp;nbsp;nbsp;^

amp; CD A,'»

s

Cafus

cum


Ja.


Uk


‘--ZO XX—^/yrauts^alfumptaeritpro^ nbsp;nbsp;nbsp;f,veIpro^ aut

^ nbsp;nbsp;nbsp;bx ¦nbsp;nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;.ernbsp;nbsp;nbsp;nbsp;•

pro 7 fi — fi c. Et qnidem primo fi z. adumpta fit proƒ U

ducenda eft per pundum A reda A D ipd B E panllela 8c ZO c; ita ut,d ,eftierit alTumpta pro7^— c, praedidum pundum D cadatnbsp;ab eadem partelinese AB, qua datus vel conceptuseftangulusnbsp;A BE. Sin contra z fuerit afiümpta pro ƒ lt;•, idemilludpun-

dutn

.#

§• I

-ocr page 349-

Lib. II. Ca p. IV. 3x1

dumD reperiaturab altera parte lines A B.Deinde per punftutn D dufta reda D K ipft A B parallela, qus fecet redam B E pro-dudam, fi opus fuerit, in pundo K: erit defcribends Hyperbola:


jno H- affedus fit, in reda D X. fin s ff figno—affedus fit, in prsdidanbsp;S snbsp;nbsp;nbsp;nbsp;tcda

-ocr page 350-

311 Elem. Cvrvarvm

refta DK; itautad eafdem diametros ordinatim applicataean-gulosfaciant, dato vel aflumpto angulo A BE vel DKE five DXEsequales. Eritque cafu utroque D centrum, amp; femi-latus .tranfverfiim ZD f, quod in didis diametris refpedivè pernbsp;lineas D V vel D L exprimatur ; eritque porro tranfverfi late-ris ad redum ratio, ut/ad^. Sienimdefcriptaintclligatur pra:-dida Hyperbolaper pundumV inutraque diametro, versus Xnbsp;amp;Krefpedivè, eademquefecare fupponaturredam XE, utamp;nbsp;ipfamKE, addidasdiametros ordinatimapplicatas, in pundonbsp;E: erit D A X five K B E coj c,amp;cDX feu K E co/c; ideo-que eadem D A X amp; K B E vel D X amp; K E ea ipfa, quje pro z eftnbsp;aflumpta: ac propterea L X oo ƒ, amp; L K oo ^ ƒnbsp;atque V X 30 —ƒ, amp; V K OO -v —ƒ:nbsp;ideoque redangula

LXVcOx:?:—ffjSiLKVoDxxff.

Cumque eadem fit ratio tam unius quam alterius redanguË LXV adquadratum XE, ut amp; utriufque redanguli LKV adnbsp;quadratum ex KE vel KB E refp^ivè, qu£ eft late ris tranfverfinbsp;ad redum, hoe eft, ut /ad^: erit quoque utnbsp;/adffjita?,?^—ffddxx,nbsp;itemque ut /ad^,itaa;a;—ffa.dzz.:nbsp;hoe eft, revocata proportione ad aequalitatem,

. Ixx nbsp;nbsp;nbsp;-r f.nbsp;nbsp;nbsp;nbsp;l XX

. ent -—ODzz —ff five zzZD -r ƒƒ,

¦ZDXX'— ff: aut, fi /fit 30^,

entzzZO xx ff amp;c zzZO XX —ff-

Quod quidem hic demonftrandum erat.

At veró fecundo, fi 2: aflumpta fit pro^ B nbsp;nbsp;nbsp;fumpto in linea

B E pundo M, ita ut A B ad B M fit, fictit ai-dh-, hoe eft, yt B M fit30^,(quod quidem pundumMjfiztaflumptafueritproj—nbsp;ab eadem parte line£E A B qua datus vel conceptus angulus A B Enbsp;fumendumeftjfedcontra,fihabeaturz:3o^ 4-nbsp;nbsp;nbsp;nbsp;, ab altera par

te ejufdem linea: AB fumi debet, ) oportet perpunda A amp; M redam lineam ducere A M, fecantem H C H amp; QF Q per prae-dida punda C amp; F dudasipfiBEparallelasinpundisGamp;N.

Quo

-ocr page 351- -ocr page 352-

314 E L E M- C V R V A R V M faciant angulos angulo A M E vel Anbsp;nbsp;nbsp;nbsp;E aequales: eritque tam

unius quam alterius Hyperbolas centrum in pundo A. Et quantum ad earundem latera tam tranfverfaquam reda, eritejus Hyperboles , quïE ad diametrum A W defcribitur, femi-latus tranf-verfum CD ƒ (idque iterum exprimatur per A C vel A F ), amp; ratio ejufdemtranfverfilaterisadredium, ut(«lt;i/ad eeg-, politonimi-rum quód ratio ipfius AB adduétam A M fitut ^ade; at verbnbsp;Hyperboles, quae ad diametrum AM defcribitur , femi-latusnbsp;tranfverfum erit AG vef AN. Quasquidem AG vel AN erit

00 ^ i cumfitut ABadAM,fiveutlt;«adfjitaA CvelAFjhoc

eft,/, adAGvel AN; amp; ratioejufdem tranfverfilateris adre-öum,uteeltidiaag. Si enimprsdidlaHyperbola defcripta intel-ligatur, tranfiensper praedidlum pundum C in diametro A W amp;per punctum Gin diametro AM, praefupponaturque redamnbsp;ME vel quot;W^E ordinatim adcafdem diametros applicatasaprasdi-

daHyperbolafecariin pundoE: eritMBEvel AXquot;'^ 00/-l-

amp; ME vel A W coj— nbsp;nbsp;nbsp;hoe eft,AX WfeuM B E,uti amp;

A W feu M E ea ipfa erit, quse pro aftumpta eft. Eft autem A M feu WE 00 ^ t ac porrb cafu priori,ubi defcripta eft Hyperbola ad diametrum A W, (cumnempe terminus ƒƒ figno eftaf-fedus) FWfiveFXWoo? /,nbsp;amp;CWfiveCXWoo^—ƒ:nbsp;ideoque redangulum

F W C velFXWCoo^^—//,amp;quadratumWEooquot;^.

Cumque fit ut latus tranfverfum ad redum, ita praedidum redangulum ad prjedidumquadratum, hoe eft, eo cafu wx. aaI ad

ee^jita: erit eelxx^:) eegz.z.-eegff,amp;,omni-

buspereej-divifis, nbsp;nbsp;nbsp;COzz.ff,ideü,z.z 30nbsp;nbsp;nbsp;nbsp; ff-

NMoo^4-^,amp; GMOO ^ ideoqueredangulumNMG 00nbsp;nbsp;nbsp;nbsp;tranfverfum ad redunü, id

eft, hoe cafu, ut e e /adj ita prasdidum redangulum N M G

ad

Atvero cafu pofteriori, ubi defcripta eft Hyperbola ad diametrum AM, cumnempe terminus ƒƒ figno — eftaffedus, erit

-ocr page 353- -ocr page 354-

^i6 Elem. Cvrvarvm

Si clcniquctertio2.aflumptafit pro ƒ B ^ 8 Cjdufta, utfu-

pra, A D co ƒ, amp; D K ipfi A B parallcla, fumptoqnc in linea K E pundio O; ica ut D Kad K O fit, ficnt;® ad hoe eft , ut K O fit

30 ^ , ducenda eft per pundia D amp; O reda D O , fecans prsedi-

diana H C H in H, atque occurrensprsefatae QJ'Q^inQ^ (Con-ftataucem exfaperius explicatis pr^edidlum pundlutn O, fiina:-

quatione habeatur— —, ab eadem partc line* A B fumendum ede, qua datus aut aflumptus eftangulus A BE; atfihabeatucnbsp;, illud ipfum pundum ex altera ejufidemUne* partc funaï

debere. ) Quo fado, fi terminus ƒƒ figno afFedus fit, erit dia-meterqu*fit* Hyperbol* in redaD'W. Sin contra, hoe eft, ft terminus ƒƒ’ figno — fit aÖêótus, erit ipfa in prtedida reda DO;nbsp;ita ut ad eafidem diametros ordinatim applicat» angiilos facianCnbsp;angulo D W E five D X W E,aut D O E live D ö K E aequales:nbsp;eritque tam unius quam alterius Hyperbol* centrum in pun-do D. Et quantum ad earundem latera tam tranfverfa quam reda, eritejusHyperbol*, qu*addiametramD Wdefcribhur,nbsp;hoe eft, cüm tcrminus//’figno afficitur, latus tranfverfum 30 ƒ-idque hicitcrum exprimatur per D V velD L, ac ratio ejufdemnbsp;lateris tranfverli adredum, utaa/adeeg; at veroHyperboles,nbsp;qu* aclgMametrum D O defcribitur, nimirum , quando terminusnbsp;ff figno —¦ afFedus eft, erit femi-latus tranFverfum reda D Q vel

D H, id eft, ^; atque ratio ejuFdem lateris tranfverfi ad redum,

xxteelxdaag. Si enim defcriptaintelligaturHyperbola, tranfiens per pundum V in^iametro D*W Sc per pundum H in diametro D O, fupponaturqueeandem Hyperbolam fecare redamnbsp;W E vel O E in pundo E,erit O K B E five D A X W ZDy c -|-

~ amp; O ^five D W30 j—c— , ac O B E five D A Wooj c

— atque O KE velD X W30J' — nbsp;nbsp;nbsp;Hoe eft, crunt

omnes ill* prsnominat* line* e*dem, qu* pro z. affumpt* funt. EftautemD Ofeii’WE30^^,ideoquequadratumWEconbsp;acporró cafuptiori, ubidefcripta eft Hyperbola ad diameirum

-ocr page 355-

Lib, II. C A p. IV. nbsp;nbsp;nbsp;3x7

D'W, cum nempe terminus ƒƒ figno . afficiciir , L W live LX'W CO z. 4-ƒ,amp; V five y X W CD z.ƒ; ideoque reftan-gulum V fiveLXWV CDZ.Z.—ƒƒ Cumque inutlatus

-ocr page 356-

3x8

cexx

CvrVarvm

: erit eelxxZDee^z ze egff,3.c,divi(is omnibus per e e£,

~ CO zz —ff,fivezzco'-— ƒƒ.'

At veró cafu pofteriori, ubidefcripta eft Hyperbola ad dia-» metrum D O, erit O O C0^^ ^,amp;HO30^ — ~ ideo-

(ld nbsp;nbsp;nbsp;CLnbsp;nbsp;nbsp;nbsp;dnbsp;nbsp;nbsp;nbsp;'

, que rcéianguIumQ^O Hco nbsp;nbsp;nbsp;¦^^^‘^^^•Cumqueiierumfit,ut la-

tiis tranfverfum ad re£tum,ita prasdiélum reótangulum QjO H ad quadratum ex OKBE velOE, five O BE autOKE: id eft,

eo cafüjUtgg nbsp;nbsp;nbsp;adg,^: erit quoque proin-

Az e elzzCO eegxxeegff Hoe eft,divifis omnibus per

erit nbsp;nbsp;nbsp;COgt;xx‘ff. Qiiasquidem omnia funt, qusecafu fupe-

riori in triplici fua diftindione determinanda ac demonftranda erant.

Ca/Fw Si vero quantitatum incognitarum ab initio conceptarum, al-l'quot;quot;'tera ex tequatione fublata, aliaque ejufdem loco feeundümRe-

Hyper- gulam affumpta,sequatio fitƒƒ CO — ff,iii eft,jj —ff CD

a.in~covv—-/y’jatqueipfa-z/tantümafllimptafitproa: ^

aliquaquantitate, Sitt/affumptaprox^h;Hoeeafuinlinea AB vel eadem produda fumendum eft punótiim I, ita ut A‘ï fit 00 ^nbsp;(quodquidem pundum I, fit^ affumpta fueritpro X'h, ah Anbsp;versus B; Sineontra, ab altera parte pundi A inproduda BAnbsp;fumi debet. ) Quo fado, erit idem illudpundum leentrum de-• fcribendasHyperbolcs, amp; , mutatismutandis, easteraomnia, utnbsp;fupra eafu iquot;°memoratumeft, nempe, diameter inredalY velnbsp;, in reéfal B, femi-latus tranfverfum 00 ƒ, atqueproportio laterisnbsp;tranlverfi ad redum, ut /ad^.

Cafus Si denique quantitatum ineognitarum, primo eoneeptarum, lofj/*'”nbsp;nbsp;nbsp;nbsp;exxquationefublata, aliisque earundem loeo juxtaRe-

affumptisjtequatio fits^oo nbsp;nbsp;nbsp; ƒƒ, (ideft,—ƒf 00

ivv nbsp;nbsp;nbsp;l ZK

-j- }, aut —'Xiv Vff-, atque ?, primüm affumpta fit pro^ fj c,

dueenda eft utrinque I R parallela BE, amp;00 e: quo fado, e-rit idem iJlud pundum R eentrum, amp; diameter in reda RY

• nbsp;nbsp;nbsp;vel

-ocr page 357-

L I B. II. Cap. IV. nbsp;nbsp;nbsp;5x9

vel R K,ejufquc femi-latus tranfvérfum ZOf,^c ratio tranfver-filateris adredum, ut/ad^. quetnadmodumeaomnia, mii-tatismutandis, calufecundo§. i.fufiüscxplicatafunt.

§. gt;. At fi z. afllitnptafueritpro/ ^ 7 gt; erit pundum S, in fmlLnbsp;nbsp;nbsp;nbsp;T tnbsp;nbsp;nbsp;nbsp;^«10

-ocr page 358-

35° Elem. Cvrvarvm

quo MA, velqusE ipfiin direöum adjungilur, pef prasdidlam IR, vel eandetn produflam, fi opus fit ,.»nterf€catur, centrum fe-öionis; amp; cstera omnia, mutatis mutandis, ut fupra cafu fecundonbsp;§. 2. memoratumeft. Nempeedtfedionis diameter inreólaSP

vel S M(atque ut ibidem A M feu E W erat CX) nbsp;nbsp;nbsp;jita hïc S M feu

EPeritCO ^ : cumfitutABadAM,hoccft,utlt;iade, itaBI, hoe eft, '2/, ad S M); eritque porrb femi-latus tranfverfum OQ ƒ amp;nbsp;refpcJiivè, acratiotranfverfilatcris adredlum,utaala.dee£tnbsp;vel utf adaa£.

§•3

Sideniques,3flumptafueritpro^ ^ ^ f, eritpunöumT,

in quo DO, vel quse ipfi indiredium adjungitur, perprxdi-lt;ftam IR, vel produdtam, fi opus fit, interfecatur,centrum; amp; reliqua omnia, mutatis mutandis , ut paragrapho praecedentï,nbsp;amp; fupra cafu fecundo §. 3. fufius expolitum eft. Atque corumnbsp;omnium demonftratio in prxcedentibus explicitè eft compre-henfa, cum termini amp; quantitates omnes hic cum prioribus con-veniant, excepto tantum, quód, qux ibidem defignabantur per a;,nbsp;hic finta: h, hoe eft, v. Ita enim quod ibi erat A B amp; E X 00 .v,nbsp;hic eftIBamp;EYoot'; quod ibi erat D K amp; E X 30 A',hic eft R K

amp; E Y00 t^jquod ibi erat A M amp; E W, hic eft S M amp; E P X

; quod ibi erat D O amp; E W X 7 , hic eft.T O amp; E P X 7

12


fint atque in prscedentibus etiam omninoplenèquecomprchen-dantur,fi nimirum,fubftituto per omnia x loco j amp; vice versa, ea-dem X non per redtam A B fed per earn, qus ex A ipfi B E paral-lela dueftafit, atque ƒ non per B E fed per redlam ipfi AB sqni-djftantem, defignetur, Quód hic generaliter monuiflèfuffecerit.

AUi

Quamvis autem fecundum Regulamaccidereetiampoffit, ut i-compofitafitexx ^ alia quadam quantitate, cui amp; incognitajfnbsp;permixta fitjita tarnen,ut eo cafu z. folummodo cx^ alia quantitate in totum cognita conftare queat, haudquaquam tarnen operaenbsp;pretium exiftimamus, cafus omnes eó fpeftantes fpeciatim perfe-qui: cum ex iis, quas tam in Locis Parabolicis quam in pofteriorinbsp;exemplo reduétionis sequationum ad formulas Theorematumnbsp;~ amp;:i 3“‘fuperiüs explicatafunt,iidem illi cafus per femanifefti

-ocr page 359-

Lib. II. Cap. IV. nbsp;nbsp;nbsp;331

quatuorcafus, cum Locus eji Hyperbola.

lam veto quod fupra annotavimus accidere qüoquc pofle, ut aequado fit

i.yx^off,

X. zx coff,

^.yvzoff,

4. zv:nff,

omnibusque iftis cafibus Locum quaefitum efie Hyper-bolam , ejus determinatio fivedefcriptio atquedemon-flratio ex iis, quae jam ante explicata funt, Iponte quo-queprofluunt.

Primo enim cafu, fi in redla A B fumatur A C GO ƒ, atque ex pundo C eduda redaC D,qu£E ipfi B E fit aequidiftans amp; aequalisnbsp;priori A C, hoc eft GO ƒ, per A amp; D reda linea ducatur: erit Anbsp;centrum Hyperbol*, cujus axiseft in reda A D, amp;pundumDnbsp;vertex, atque AB afymptotos. five (duda reda DF ad ADnbsp;perpendiculari ac in AB terminat^ erit A D femi-latus tranf-vcrlum, amp; ratio tranfiverfi ad redum, ut A D quadratum ad D F

jz:

/


b/


-Z


quadratum. Si namque prsedida Hyperbole fecare fupponatur redam BE inpundo E, erit ‘ redangulum ABE GO quadrato 'nbsp;nbsp;nbsp;nbsp;?

ex A C vel C D.Quarecum ABfit GO.v,B E G07,amp; A CGOƒ eritf^^'^^* GO ƒƒ• Quod primo cafu eratdemonftrandum.nbsp;nbsp;nbsp;nbsp;^

Sec^indocafu , cum nempe a;quatio eft axcoff, oportetut^ juxta Rcgulam fit afl’umpta pro ƒ 9 uota quadam quantitate. Efto

T t a nbsp;nbsp;nbsp;itaquc

-ocr page 360-

33^ Elem. Cyrvarvm

itaque affumptapro^ c, atque idcirco ad defcribendam Hyper-bolam ducatur per punöum A reda AGipfiBE parallela, ac CD c: fumpto nimirum pundo G vel ab hac vel ab illa parte linesenbsp;AB, prout c quantitas figno vel—fuerit afFcda; dudaquenbsp;porröGHipfiABparallela,centroG, AfymptotoGH, cxte-risque, utfupra, mucatis mutandis,Hyperboledelcribatur. Harenbsp;igitur fi fecare fupponaturredam B E in pundo E , eritredan-gulum G HBE velG HE x//VndecumfuGH X v, amp; HEnbsp;vel H B E X j n c, id eft, : erit G H E vel G H B E redangu-lum COZ.X, ac propterea X ff- Quod 2‘^“cafu demonftran-dumerat.

Tertiocafu, nempefisquatiofitjt'X//: z/quoque tantum pro X ^ nota quadam quantitate fumpta iit oportet, veluti pronbsp;X ^ h. IdeoqueadinventionemLociquaEfiti, inredaA B velinnbsp;ipsa produda furaenda eft AI X ^ , ac porró centro I, atquenbsp;Afymptotol ABvell B, exterisque, uti'upra, mutatismutandis, dcfcribendaêft Hyperbola, quïefiredam B E fecare fuppo-

natur in E: erit redangulum IA B E vel IB E X ƒƒ. Quare cuin IA B vel IB fit X at ^ h, hoe eft, t/, amp; BE X ƒ: eih^vzoffnbsp;Quod 3 cafu demonltrandum erat.

Denique quarto cafu, fi nempe asquatio CitzvöDff: erit z. af-fumptaproj’ f3 c,amp;v'^'cox ^h.Ideoqueperpraedidum pundum I ducenda eft I KipfiBE a:quidiftansamp;xc;dudaqueKH ipfi ABnbsp;parallcldjCCntro K,atque Afymptoto K G H vel K H, eseterisque,nbsp;ut cafu i™, mutatis mfitandis Hyperbole defcribenda eft, qu^nbsp;fifecarefupponaturredamBEinÈ! erit redangulum KGHEnbsp;velKHE.utamp;KGHBEvelKHBEx//. HinccumHBEnbsp;vel H E fit zoy R c, id eft, ?,, amp; K G H vel K H X-v fj /ï,hoc eft,nbsp;V. erit 2. V ZDff Q,uod 4'° cafu demonftrandutn erat.

Atque ba:c quidem omniafunt, quse circa inventionem Loco-rum eo cafu, quo iidem funt in linea Hyperbolica, confideranda veniunt.

Altero autem cafu generali formularum fub N'’°3. compre-henfarum, cüm nempe terminus, in quo invenitur a; ar vel vv Cigna — fit aifedus, ac proinde Locus quxfitus vel Ellipfis vel Circulicircumferentiaexiftit, fi inaequationefradioreperiatur,nbsp;rejki quoque illa poterit majoris perfpicuitatis gratiaintermi-namyj/ydzz- Quo fado primo, remanente utraque quantitate

inco-

-ocr page 361-

Lib. II. Cap. IV. nbsp;nbsp;nbsp;333

incognita ab initio concepta,^fequenti formula fe cxhibebitse-quatio '^ffxx’. critque,utin fequenti figura, defcribendsc

Ellipfeos diameter in reda A B.quse pro*^ indeterminate eft con- Locus-vel cepta, itaut adeandem diamecrum ordinatim applicatse cum eanbsp;angulos faciant, dato vel aflumpto angiilo ABE sequales j ac cen-trumin pundoA, amp;fcmi-latus tranfverfum ZDf- idquodindi-da diametro per lineam AC vel A F exprimatur, eritque rationbsp;cjufdem tranfverfi Kiteris ad redum, ut / ad^.

Si enim defcriptaintelligatur prasdida Ellipfis, tranfiens per punda C amp; F, fccansque applicatam B E in pundo E: erit F Bnbsp;00/ arjamp; B C ZDf-—xx ideoqueredangulumFB Ccoff-xx.

At cum ex natura Ellipfeos, lateribusredotranfverfoque aequa-libus, prasdidumredangulum FBC “fit OOquadratoex BE,‘jigt;fyi}

hoceftj^j: eritquoqueproindeeocafu ƒƒ nbsp;nbsp;nbsp;—xx. Etfacile

H

apparet, ft, iifdem pofitis, BE fuper redamFC foretquoque perpendicularis, hoc eft , ut angulus quern ordinatim appUcatsnbsp;faciuntad diametrum fitredus, praedidam curyam fore Circuli

circumferentiam.

Cumautemporro, lateribus tranfvcrfo rcdoque injequalibus

T t 3 nbsp;nbsp;nbsp;atque

-ocr page 362-

534 Elem. Cvrvarvm

t per If atque in ratione ut / ad^, eademfit ratio ' reöanguli F B C ad frmihu- BEquadtatum, quae eltlateris. tranfverfi adreótum, hoccft, utnbsp;]'“• l ad^: ex ptirdiftispalam eft fore ut l ad^, m ff—x

hoc eft, efte ZDff--xx. Qiiod eo cafu dcmonftrandum erat.

Cafus Atfi, quaiuitatum incognitarum primo conceptarum una ex

1''quot;*, ra'w jEQuacione fublata aliaque in ejufdem locum jtixtaR* gnlam af-Locusefi nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;. /yynbsp;nbsp;nbsp;nbsp;er

fumpta, Ecquatio fit-— 00/ƒ—Arar: aut?,aflumpta eritpro ƒ

•vel Circuit nbsp;nbsp;nbsp;h x. ^nbsp;nbsp;nbsp;nbsp;hx

cnmmfe. autprojy ~ , autproj R C 8 v •

§. I. Etprimümquidem, fis,aflumptafueritpro^ ^ c,ducendaeft per punóèum A rcéla AD ipfi B E parallela ac OO c j ita ut, fi «.nbsp;fuerit afiumptaproj—c, prjediótum punftum D cadatab eademnbsp;partelinex AB, quadatusvel conceptuscft angulusABE; finnbsp;contra z. fuerit aflumpta pro ƒidem illud puntSum D ab altera parte lineae AB reperiatur. Deinde dudla perDredlaDKnbsp;ipfi A B parallela, quse fecct redèam B E , produdfam,versus B, finbsp;opus fuerit, in punólo K, erit quxfits Ellipfeos diameter in reétanbsp;DK, adquamordinatimapplicatsecnmeaangulosfaciant, datonbsp;velafl'umpto angulo ABE feuDKE xquales. Punélumautemnbsp;D centrum erit, amp; femi-latustranfverfum oo ƒ. quodindidisnbsp;diametrisperlineasD Vamp;D Lexprimatur, eritqueratio tranf-verfi lateris ad rcdura, utVad^.

Si enim praedida Ellipfis defcripta intelligatur tranfiens per punda L amp; V, quae fupponatur fecare redam B E, ad praedidamnbsp;diamctrum ordinatim applicatam,in pundo E: eritK B E OO7-I-C,nbsp;amp; K E 00 J — idcoque eadem K B E vel K E ea ipla, qux pro z.nbsp;aflumptaeft. CumqueLKfitoo/ a:,amp; KV 00ƒ—x\ eritre-dangulumLK V ZOff—xx. Atcum eadem fit ratio didi re-

danguliLKVadquadratum exK BE velKE, hoccft, ad?,;?., qu£E eft lateris tranfverfi ad redum, hoe eft, ut /adj-: erit ut / ad

gj ii^ff—a;a;ad?,?.,hoceft,erit^ 00 ƒƒ—xx. Quodquidem,

fi / fit 00 idem eft ac ? ? CD ffxx. Atque hïc iterum facile ap-parct, quód, exiftente angulo D K B E vel D K E redo, amp;clco gt hoccft,rcdanguloLK V 00 KEquadrato, prsedidacurvaCir-culusfitfutura.

§.a.

Atverojfiiaflumptafueritproj 8 nbsp;nbsp;nbsp;fumptoin linea BE,.

prb-

-ocr page 363-

Lib. ïI. Ca p. IV. nbsp;nbsp;nbsp;335

prodmfta vtrsus B, ü opus fuerit, punóto M; ita ut A B ad B M fitjficutrfad^, hficeftjUtBMfit X ( quodquidcmpundutn

M,fi«,afliimpta fuerit pro ƒ— — ,abeademparteIineaeAB, qua datus ve! conceptus eft angulus A B E, fumi debet j fin contra, znbsp;pro^ -^ aflurnpta fuerit, ab altera ejufdemlines A B parte fu-

mendum eft) oportet pcrpunéia Aamp;M recftamlineamducere N A M G , fecantem redam H C H , atque occurrcntetn ipfinbsp;Q-F Q.» qua? per prsdida punda C amp; F ipfi B E duds funt squi-diftantesjin G amp; N. Quo fado, eritqusftts Ellipfeos diameter


iP


inreda NG, ita ut ad eandem diametrum ordinatim applicats cum ea angulos faciant, angulo A ME vel AM BE Srquales.nbsp;Porró centrum ejufdem erit in pundo A, amp; femi-latus tranfver-fumerit redaANvelAG. (qusquidem AN vel A G, ft ratio

AB ad AMfupponaturut^ adf, squabitur ^: cum fit ut A B

adAM, fiveutlt;ïadf,itaAC,hoeeft,/adAG.) Deniquera-tio iranfverfi laterisad redumeritut eelaagy id eft, ll/fit

OOI,

-ocr page 364-

33^ EleM. CVRVARVM

CO^, five, qupd idem eft, fitermino zz nulla adhireat fradiö,

utff ad4lt;*,lioceft, ut A Mquadratum adquadratum A B.

Etenim fi prïdiéla Ellipfis defcripta intelligatur tranfiens per N amp; G , lupponaturque eandem fecare reétam M E^ velnbsp;M B E, ad praeditilam diametrum ordinatim applicacatn in pun-

öo E: erit eadem MEoov — ^jamp;MBEoov l-*, ac proinde ea ipfa, quae pro z aflumpta eft. Cumque AM fit COnbsp;^, erit NMco^ ^,amp;MGco^ — ideoque reólan-*

pulumNMGco nbsp;nbsp;nbsp;. At cum eadem fit ratio didire-*

° nbsp;nbsp;nbsp;aa aa

/ J nbsp;nbsp;nbsp;• ef/Y-

li.dieicquot; nbsp;nbsp;nbsp;•

danguli NMG ad quadratumex MBE vel ME, qu* eftla-teris tranfverfi ad redum, hoc eft, eadem qua? t £'/adlt;*4^: crit

quoque ut^e

! ag, uta

ad?,?., aeproindee^/^,?;

Ikk

CO e egffeegxx. id eft, fada diviGone per eeg, erit

CO ƒƒ— XX. five, pofitalZDg,z.züD ffx a;,Vnde ex ante di-dis iterum apparet,quód fi angulus A M B E vel A M E redus fir, acfimulee/CO hoc eft, redangulumN MG CO quadratonbsp;ex M E vel M B E, praedidam curvam fore Circulum, cujus centrum fit A, amp; femi-diameter A N vel A G.

i X nbsp;nbsp;nbsp;^

§¦ 3‘ nbsp;nbsp;nbsp;Deniquefi tertiocaffumptafit pro^ {3 R ^ , duda, utfu-

pra, A D co ƒgt; amp; D K ipfi A B parallela, fumptoque in linea K E pundoO, itaut D K adKO fit, ficut4ad^, hoc eft, utKO

fit CO ^ : ducenda eft per punda D amp; O reda Q_D O H, fecans

prardidam HCHinH, atqueoccurrcns przfatat QF Q^in Qi (conftat autem exiis , quae jam fspius monitafunt, fi habeatur

¦—^, praedidum pundum O ab eadem parte linea: D K, qua datus vel affumptus eft angulus DKE, fumendum efle; atfiha-bcatur ^ , illud ipfumab altera ejufdem linea: parte fumidc-

bere.) Quo fado, erit deferibendse Ellipfeos diameter in pra:-dida reda QD H, ita ut ad eandem diametrum ordinatim ap-

plicata:

-ocr page 365-

Lib. II. Cap. IV, nbsp;nbsp;nbsp;33T

plicat* cum ea angulos faciant, angulo D O K E vel D O E «quales. Porro centrum erit in D , amp; femi-latus tranfverfum

D (^vcID HxANfeuac ratio tranfverfi laterisad reftum, ut ee/ ad aa^.

Si enim quajfita Ellipfis defcripta intelligatur , tranfiens per punda Q^amp; H, eademquc fecare fupponatur redam OE vel

OKE in pundo E; erit OKBE 00/ c OE X


j—c— —,0BEx^4-c—- — , amp; OKEx/*—c

hx

^ : ac proinde prsnominatae ilk lines eaedemerunt, quspro

z. aflumpts funt.Cumquc porro fit D O feu A M X , ideoque

Q,Ox^ ^’‘, amp;OHx^ nbsp;nbsp;nbsp;^ : critredangulumQOH

OO nbsp;nbsp;nbsp;• At cum eadem fit ratio didi redanguli Q^OH

Tars II, nbsp;nbsp;nbsp;• Vunbsp;nbsp;nbsp;nbsp;ad

-ocr page 366- -ocr page 367-

Lib II. C A P IV. nbsp;nbsp;nbsp;359

vel, quae ipfi in direSum adjungitur, per praediftam IR, prodiJctam, fiopusfueiit,interfecatur, centrumEilipfeos;nbsp;Sc caetera omnia , mutatis mutandis, ut fupra cafu fecun-do §. 2. memoratum eft. Ncmpe erit fedionis diameter

inredaSM, (atqueutibidemerat AM 30 itahxcSM

crit ^ : cum fit ut B A ad A M, hoc eft , ut 4 ad lt;?, ita BI, id eft, V , ad S M: ) eritque porro femi-latus tranP-

verfumoo amp; r^tio tranfverfilateris ad redum, ut ad a ag.

hx

§. 3. Denique fi z. aflumpta fuerit pro^' ^ nbsp;nbsp;nbsp;gt; erit pun-

dumT, inquoDO, vel, quaeipfiin diredumadjungitur, per praedidam IR , produdam , fi opus fuerit, interfeca-tur, centrum Ellipfeosj amp; reliqua omnia, mutatis mutandis, ut paragrapho prsecedenti ac fupra cafu fecundo §. 3

V u 2 nbsp;nbsp;nbsp;fufiiis

-ocr page 368-

340 Elem. CVRVAR, Lib.II. Cap. IV.

fufiüs explicatiim eft. Nempe erit diameter in reda T O , amp; femi-latus tranfverfumnbsp;nbsp;nbsp;nbsp;ratio tranfverli lateris ad re-

öum, ut e e l nbsp;nbsp;nbsp;Atque eorum omnium dcmonftratio

in prarccdentibus explicitè eft comprelienfa , cum termini amp; quantitates omnes hic cum prioribus conveniant; excepto tantum , quod qujE^ ibidem defignabantur per x hic defignenturnbsp;perx f5 h, hoe eft , v. Itaenimquódibi erat AB co x, hic eftnbsp;IB CO j quod ibi erat D K X JTj hic eft R K co ï' ; quod ibi erat

; amp; quod ibi erat D O X ^ , hic

AMx -^hic eftSMx‘'‘

eft TO X

Qiiat quidem omnia funt, qu$ circa inventionem Loei illo cafu, quo idem vel Ellipfis vel Circulicircumferentia exiftit,nbsp;confideranda veniunt.

Atque ita generali Regula cafus omnes inveniendi Loca per squationes, in quibus neutra quantitatura incognitarum in fenbsp;duébi nee fadtum fub iifdem ad tres dimenfiones afcendit, fednbsp;vel qiiadratum vel planum nonexcedit, complexifumus.

FINIS.

-ocr page 369-

F R A N C I S C I a S C H o o T E N,

L E I D E N S I S,

dum viverei in Academie Lugdmo-Batava Mathefeos ProfejforiSy

TRACTATVS

D E

CONCINNANDIS

DEMONSTRATIONIBVS

GEOMETRICIS ex Calculo Algebraïco.

In lucem editta

\

a

PETRO a SCHOOTEN, Francifci Fratre.

Hx Typographia Blaviana,m dc lxxxiil

Simptibus Societatis.

-ocr page 370-

Kobilijjlmïs ^ SplendtJJlmisViris, Academia Lugdu-nenjls Curatoribus vigilantijjimïs,

D. AMELIO aBOVCHORST, Wimmetiumi Domino, de ördine Eqiieftri in Delegatos Prspoten-tium Hollandis Ordinum adfcripto, amp; ejufdemho-noratiflimi Collegii Prxfidi, Rhenolandise Aggerumnbsp;Com id, amp;c

D. G E R A R D O S C H A E P, I. C. Cortenhoevii Domino, Exlegatoad SereniflimosDaniaeSueciaequenbsp;Reges, antehac in Confeilu Ordinum Generalium amp;nbsp;Collegii Ordinum Hollandiae Confiliariorum Dele-garo, Magnificaeque Reip. Amfteljcdamenfis Excoii-fuli, amp; nunc ^rarii urbani Praefecto.

D. CORNELIO DE BE V ERE, Equiti Aurato, Screvelshoeckii, Weft-illelmondae, Lindas, amp;c. Domino , Exlegato ad Sereniiïimos Magnas Britannije Da-nixque Reges , Exconfuli prims in Hollandia Dor-drechtanorum Vrbis,in Concilio Prspotcndum Hol-landias Ordinum ordinario Aflellbri.

EORVMQVE COLLEGIS,

A7tiplilJimis,SpeClatiJ]imifque,florentiJ]i7nte ReipublicaLeiden^s Confulibus,

D. CORNELIO a BVYTEVEST.

D. GVILHELMO PAETS, I.C.Aggerum Rhenolandiae Chomarcho, amp;c.

D. PAVLOaS\CANENBVRG,I.C. in Prs-potcntium Foederati Belgii Ordinum Confeffu Hollandias nomine Delegate Afleflbri.

D. RIPPARDO a GRCTENENDYCK, I.C

NEC NON

Ampltjjimo, ConfulttJJlmoi^fte VirOy

D. lOHANNI a W E V E I,IN CH O VEN, I.C. Reip. Leidenfis Syndko, amp; D D. Curatoribus a Secretis.

Nobi-

-ocr page 371-

HobiltJJiwi atque AmpUJJïmi Viri, ‘Domini ^lurimum honorandi,

? {

Eminam affequends veritatis metho-dum, quarum altera Synthefis five Compofitio difta, altera Analy fis vo-cata five Refolutio , cumprimis innbsp;Mathefi a Vereribus frequentacamnbsp;tritamque fuiflè , palam facitmt ce-lebria eorundem monumenta. Quorum imitari exemplacupiens meus p.m. Frater, poil-quam methodo Synthetica fcientis hujus prjeclara multanbsp;publicis ram fcriptis quam prasledionibus cum fruétunbsp;tradidifiet, ad Analyfin quoque, certifiimam inveniendinbsp;artem, ejufque perficiends rationem fua ftudia conver-tit. Nequedubitabatquinpleraque omnia , quaeVeteri-bus tantum glorise peperilTent, Analyfeos beneficie acnbsp;ope reperta eflent: fed quae illi, ut inventorum majornbsp;admiratio foret, diffimulato hoe at tificio amp; fupprefib,nbsp;vulgaritantum Synthefeos forma exhibuiflent. Sed cumnbsp;Veterum diflTimulatione faftum videret, huncAnalyti-cae methodi praeftantem ufum non modoamultisigno-rariac negligi,fedipfam ejus certitudinem ac evidentiamnbsp;a nonnullis fufpeftam haberi, atque adeo foliSynthefinbsp;miferando labore inhaereretur: confultum judicavithacnbsp;peculiari diatriba ofténdere, ipfum quoque Syntheticumnbsp;demonftrandi modum in Analyfi contineri, atque ex eanbsp;elici pofie; ut eo argumento quemyis convinceret,quan-tumillaamp;prxvaleat, amp;prxferendafit. Sedvixhuic tra-^latuifupremamimpofucratmanum, cum, proh dolor,nbsp;vita ejus , atque omnisreliqua de eo expeftatio, intercedente faro abrupra fuit. At vero, utpofthumus idem atque novifiimus induftrix ejus foetus in publicam lucem,nbsp;cui deftinatus erat,rite amp; honefte prodire poflet: ego, ut

(Icfun-

-ocr page 372-

^efunfti frater unicus , mei eilè officii atque pietatis exi-ftimavi, non tantum in me recipere editionis promovendae ac juvandae curam; fed etiam pro veneratione amp; ob-fervantia , quaevobis , Nobiliffimi atque Ampliffimi Domini, jure multiplici debetur , eundem foetum inclytae di-gnitati veftrae ac honori conlêcrare. Vtique futurum Ipero, ut cujus ingenii primitias, illuftribus veftris no-minibus olim infcriptas, propitia benignitate excepiflis,nbsp;hunc q«oque ultimum ejufdem fruftum gratiofe fulcipia-tis. Neque folita liumanitas veftra obftarefinet meamnbsp;ofFerentis tenuitatem, qui fimul hoe quantulocunque co-natu pro veftris non modo in Fratrem, fed etiam in p. m.nbsp;Parentem meum, longi temporis beneficiis meritifquenbsp;gratum animum profiteri ac teftari exoptem. Quod qui-dem pro illis, meque ipfb, luculeiitius aliquando me fa-«fturum confido, fi amp;mihi, a prima aerate fimiiibus ftu-diis innutrito , benevolentiae amp; favoris veftri auramnbsp;afpirare contingat. Interim Devm Opt. Max.nbsp;fuppliciter oro, ut confilia veftra amp; pro Reip. falutenbsp;atque Academiaedecore curas fecundet, optimifquefuc-ceflibus donet.

VeJlrarumNobb. amp; Ampp. humillimüs diens

PeTRVS a SCHOOTEN.

FRAN-

-ocr page 373-

FRANCISCI a SCHOOT EN

Trai^atus

De concinnandis Demonftrationibus Geo-metricis ex Calculo Algebraïco.

Lectori S.

Voniam, qm m TraBatu hoe do-centur, e'videntius ^er exempla qudm Ipr^ceptaexplicari atque intelligifof-funt: fuseere judka^i -variis diver-Jorum generum exemflis rem apertijjimè ex^one- •nbsp;rej candidéque im^ertiri. l^ale.

P R o B L E M A.

Datam relt;?tam A B, utcunque fedam in C, ita produ- vue fi-cere ad D, ut redangulumfub A D, D B comprehenfum iequetur quadrato redse C D.

Series Analyfeos five Refolutionü,

Suppofito Problemate ut jam faöo, voco A C. ^

C B. è

amp;BDvel DE. Arreritque AD.lt;j ^ Ar,amp;CD./^ ,v. Deinde ut habeatur xquatio,

Multiplico AD. rf ^ A* perBD vel DE.nbsp;nbsp;nbsp;nbsp;a

.Eritque redangulum fub A D,D B cotiv^

prehcnfum,hoc eft,a A D E F.^ .v ^ a a: at.

Fm II. nbsp;nbsp;nbsp;Xxnbsp;nbsp;nbsp;nbsp;Si-


-ocr page 374-

340 De concinnandis

Similiter, multiplico CD. b x per C D yel D G. ^ a; ¦

bx-{-xx bb-\- hx

Et fit quadratum ex C D, hoe eft,DCDGH. nbsp;nbsp;nbsp; a;a-.

Vnde talis emergit squatio

ax^\^bx¦\-xx^bb•\‘^bx•^xx.

Adquamreducendam tollaturutrinquebxicxx, eritque ax’Xgt;bb-\-bx'. t

Deinde transferatur ^ -v ad alteram partem, ut incognita quan-*' titates ab una amp; cognitge ab altera parte habeantur,

amp;fit A X—b xZD b b.

Cujus utraque pars fi dividatur per a — ^,

invenietur.V00 nbsp;nbsp;nbsp;• Hoe eft, refolutaaequalitatc

in proportionem, crit ut ab ad b , b ad ar.

ld quod docet, adproducen-^ dam A B ufquc ad D, qualis re-H nbsp;nbsp;nbsp;.ö quiiitur , fumendam effe C I te-

I nbsp;nbsp;nbsp;qualemCBjitaut AIfi:oolt;ï—b-,

I ac deinde ad AI amp; IC vel C B, 1 hoe eft, ad 4'— b Sc b, effe inve-..!j) niendam 3''“quot;’ proportionaletnnbsp;I ï cnbsp;nbsp;nbsp;nbsp;Ij; BD.

: nbsp;nbsp;nbsp;Vnde tale formari poterit

^ : nbsp;nbsp;nbsp;..................Theorema, fupponendo reftan-

gulum A D B quadrato ex C D jequale effe.

Si A B próducatur ad D , ita ut reftangulum A D B fit leqüale quadrato ex C D : erit A C major quam C B,nbsp;amp; exceflus A I ad I C vel C B eandem habebit ratio-nem, quam C B ad B D.

fequendo nimirum ejufdem veftigia ,hoc paclo:

Cujus demonftratio eodem ordine procedit quo Analyfis,

Cum

-ocr page 375-

Demonstrationibvs. 347

Cum enim ex hypothefi O A D B fit sequale ex C D,

ax-\-hx xxZDbb ihx-^xx ablato utrinque CZl'° fiub C D amp; D B,nbsp;hx-\-XX

apn I _/?-cundi.

erlt '* ? fub A C amp; D B xquale en'® fub C D amp; C B ^ ax 00 bb bx.

bper lyc-

Riirfus auferatur utrinquecu] fub I C vel C B amp; B D,id eu,^ a', cmdi, eritque ' co fub A ramp; B D sequale ?“ ex C Bnbsp;nbsp;nbsp;nbsp;^

^ Xb X 00 b bgt; nbsp;nbsp;nbsp;cundi,

cundi.

Ut A I ad I C vel C B, ita C B ad B D

Hoe eft, refolutasqualitatein proportionem , crit' nbsp;nbsp;nbsp;dper ^fe-

e per ly

aégt;---bj X. Qiioderatpropofitum./’xi;’.

^oniam autem fraflare videtur, loco horum aqua-lïum reBangtilorum confiderat^e laterum^rofortioneniy quandoquidem ïn demonjtrationibus GeometriciSy ubi hanbsp;aqualitates velfroportiones fchemattm contèmplationinbsp;infuper Jiint aftringenda , linearum hac inter fe collationbsp;Jïmplicior ejt cenfénda qudm planorum aiit folidorum,nbsp;ip/dque etiamfiguras requïrit mms ïntrïcataSy velfal~nbsp;tem ratiocinationes, qua circa illas jiunt, magis liber asnbsp;reddit: idcirco convertenda erit aqualitas in proportio-nem atquehcec eoufque continuanda varièque tranfinti-tandayiitendo fc. adidmodis argumentandi libro 5quot; E-lementorum expojitis, donee afpareat qiiajïtum ex tri-bm prioribmproportionü terminis conjiare feu inveniri ¦nbsp;poffe. fpuod ipfum ut reEliüspercipiatur ,vifum nobis fuitnbsp;aliam pracedentis Theorematis demonftrationem htcnbsp;afferre, qiialis ill a d principio ufquead finemperpro-portionalia procedit, prioribus cequalitatibus adnbsp;amujfm rejpondet.

ex C D :

bb-\-ibx xx'.

Xx a

Erit

Etcnim cum ex hypothefi fit • CO A D B asquale

4X ^X A'.V 00

-ocr page 376-

348 De concinnandis

£ per 17 Jèxti.

Êrit^, refolvendo xqualitatem in proportionem, ut AD ad CD, ica CD ad BD.

a l; x——h x-b x / x.

Hinccumfit

ut totum A D ad totum C D,

a b x--b x

itaablatum CD adablatumBD :

b x - X

% per 17 entetiam *

^uinti. reliquum A C ad rcliquum C B,ut ablatum C D ad ablatum BD a -- b -- b x / X.

h per 17 Et dividendo *

iuinti. nbsp;nbsp;nbsp;Ut AI ad IC vel C B, ita C B ad B D

a—b —— b '—¦ .b ! AT. utproponebatur.

Hinc.utProblemati huic fit locus, pater, reöam A C ipsa C B debere efle majorem ; atqueadebhanc conditionemProblcmatinbsp;ellc prxfigendam, cum fme ea conftarenequeat, fi velimus utnbsp;^nbsp;nbsp;nbsp;nbsp;^ quaefitum ex datis inveniatur, ut-

pote ad quod obtinendum B C ex C A eft fubtrahenda.

iper 6 fecundi.

Idemetiamliquet, fupponen-do A C asqualem aut minorem quamCB. Nam A Cjequaliexi-, ftente ipfi C B , non poflet re-’ .{ftangiilum A D B quadrato ex

p -----------------------C D acquale efl'e: cum illud ’ una

cum quadrato ex C B ei tantum aequale cxiftat. Et quidem ft A C ipsa C B minor (It, manifeftumnbsp;eft, reiftangulum A D B quadrato ex C D tunc adhuc multo minus fore.

Cum igiturconftetDeterminatie, Problemaconftrueturhoc modo;

ConjlruEiio.

AfTumpt^ C I aequali C B, fi fiat ut reliqua AI ad IC vel C B, ita C B ad B D: dico redangulum A D E F,

quod

-ocr page 377-

DemonstrationibvS. 349 quod fub A D amp; D B feu D E comprehenditur, aequalenbsp;effe quadrato C D G H, a refta C D defcripto.

Nota Hujus at-que fe-

quentium

Proble-

Quadipftim retrograde ordine fit manifeftum, incipierido ab Analyfeos fine amp; per ejufdem veftigia redeundo ad illius prin-cipium.

Finis Compojïtionis,

habebitur ^

cm fub AD amp; D Bfeu ADEF squale ?'“ex C D feu CDGH'. matum

Ax-^bx-\-xX nbsp;nbsp;nbsp;Xnbsp;nbsp;nbsp;nbsp;bb-\-rbx-^xx. uo^^^K-

Quod arat faciendum. nbsp;nbsp;nbsp;legen-

. nbsp;nbsp;nbsp;das eiiè.

Rurfiisadditoutrinquecl3'“fub C D amp; D B, ideft, nbsp;nbsp;nbsp;kpfnyê'

• nbsp;nbsp;nbsp;curtdi.

fict” cmfubACamp;DBatqualecm'“fubCDamp;CB Iperife. axnbsp;nbsp;nbsp;nbsp;Xnbsp;nbsp;nbsp;nbsp;bb-drbx.

ni per t

n per 3 fi-cundi. o per 17nbsp;fexii.

Deinde addito utrinque fub I C vel C B amp; B D,id eft, b x, ut fecundi in alteram tranfeat partem,

erit'. emfub A I amp; BD sequale nbsp;nbsp;nbsp;ex CB.

axbx nbsp;nbsp;nbsp;Xnbsp;nbsp;nbsp;nbsp;bb.

revocata proportione ad sequalitatem,

ut AI ad IC vel C B, ita C B ad B D:

ab—'— b--b t X

Etenim cum ex Conftruftione fit

Principium Compojitionis.

Alia ejufdem Problematis Compofitio, per veftigia pro-. portionalium fecundse Refolutionis regrediens.

I

Finis Compojitionis.

erit^afub AD amp; BD feu ADEF atquale ex CD feu CDGH.

ax bx-\-xx X bb’^rbx-\-xx.

Quod erat faciendum.

id eft, revocata proportione ad a:qualitatem,

ent

Xx 3

-ocr page 378-

550 nbsp;nbsp;nbsp;De concinnandis

•q pmi critcttam ¦!

quinü. lu AD fumma antec.adCD fumraa conf.,itaCD una antec.ad BD

unam confeq.

a h x--^ A- - h-\-x..... .V

ita C^D anteced. ad B D confequentem:

b x---X

Hinc cumfit ut A C antec. ad CB confeq.,

a. ——- b

ut A C ad C B, ita C D ad B D.

a-b- b-^x/ X.

^ nbsp;nbsp;nbsp;eritcomponendo '

qHinti. nbsp;nbsp;nbsp;Ut AI ad I C vel C B, ita C B ad B D:nbsp;nbsp;nbsp;nbsp;•

ab--—b --b! X

Cumenimexconftruélionc fit

Principium Comfojitionis

His igitiir ita fe liabentibus, fi velimus, ut, negle(3:o artifiicio, quo mm Conftrudio Problematis, turn ejus demonftratio fuit iii-venta, tantummodo conftet, allata Conftrudlione qusefitum fem-pcr obtincri: poterimus, calculi veftigiis nunc prxtermiffis, hu-jufmodi ad id afferre demonftrationem.

‘Demonfiratio.

Cum enim ex conftrudtione A I fitad IC vel CB, ficut CR ad B D: erit ‘ reclangulum fub extremis AI amp; BD arquale

quadrato medis C B. Quibus li addatur cotfimune reótangulumnbsp;fub IC vel C B amp; B D, eritnbsp;amp; reélangulum fub AC amp;nbsp;B D “ aequale reftangulo fubnbsp;C D amp; C B. Hisigitur fi rurfusnbsp;addatur commune redtangulurfinbsp;fub CD amp;DB, erit fimiliter *nbsp;reöangulum fub AD amp; D Bnbsp;feu A D E F jequale quadrato


s per 17 fixti.


t per ifè~ cundi.

A.

cundi.


O.


% B

-i-


5C


X per I fecundi.nbsp;y per 1nbsp;fecundi.


•jD

|3C


es C D. Quod crat faciendum.


rd


-ocr page 379-

D E M o N S T R A T I o N I B V S. 3 5'!

Vel etiam Jïc:

is

11

17

Cum cx conftruöione A I fit ad I C vel C B, ficut C B ad B]gt;i critcomponendo'¦ ACadC.B , ficutCD ad BD. Sedutapfrnbsp;una antecedentium C D ad unam confequentium B D, ita funtnbsp;antecedentes A C amp; C D fimul, id eft , tota A D, ad confcquen-tcs C B amp; B D fimul, id eft, ad totam C D. ^qualia igitur limt ' c fcrnbsp;quadratum C D amp; rediangulum A D B. Quod erat faciendum.

^loniam itaqueTroblemate ad aquationem^erdiiflo Algebra mmus eji eam deinde juxta 'certalt;s regulasnbsp;tranfmutare, fervando femper aqualitatem, fic ut tandem confiet, quo paBo illius ope quajita quant it as ex data s inveniri pojjit: non inconveniens duxijlund hi» often-derem,quibus modis aliquot illius ujitatiores tranjhmta -tiones in proportiones refohi queatit,cum ba, utJiipranbsp;monitum]uit,in Troblematis Geometricè refolvendis acnbsp;inTheorematis folitomoredemonfirandis, concinnioresnbsp;Jïntpidicanda; prafertim ubi eadem aqualitas ad tresnbsp;plurefve dimenfiones afcendit, atque idcirco illa cuipuenbsp;minus obvia eft, qua ratione per Geometria Element anbsp;fitexplicanda.

Typus aliquot Kquationum, fecundüm Algebrae leges reduclarum, amp; earundem in proportiones corre-Ipondentes refolutio; tam ad Problematum Refolu-tiones Geometricas ex calculo eliciendas, quam adnbsp;Tbeorematum Demonftrationes ex eodem compo-iiendas, urilis.

crit * ut ad by ita r ad ar. j per 16

---- j

vel permutatim nbsp;nbsp;nbsp;Jèiti.

ut a ad c , ita b ad at.

cnt‘uta p^bzdcyUadadx. velpermutaüm .

uta ^ baddy 'itac adx.

ReduBiones Algebraica Refolutiones Geometrie a. Sifuerit^iA'OO^ f:nbsp;dividatur utrinque per a.

r

ntxzo ^ .

a

e per 16

Sifit^a; f5 bxco cd: dividatur utrinque per bnbsp;cd

titxzo

Si

-ocr page 380-

INNANDIS

erit ^ ut ad ^ ^ ita cadAT. vel permutatim

ut V* ad e , kz b ^ d ^èx.

erit ^ utlt;i f5 ^adc f5 e,ita ad at. vel permutatim

utlt;ï f5 ^adlt;^,itae f5 ezix,

erit'' ut^ïad^ r,ita^ — cadAt. vel permutatim

utAzdb — £•, ita^ eadAT,

erit ut 4 ad b, kz b x ad amp; dividendo ^

ut4 — ^ ad ita ^ ad a;.

f per l6 jexU.

.q fcr \6 ‘jexti.

h per i£ fexü.

hb-

i per 16 fexü.

* Vtfupra ad no-tam fnbsp;k per 17nbsp;qvinti.

1 per ig jixii.nbsp;m per i Snbsp;^u'mü.

n per 16 fexü.nbsp;o per 17nbsp;quinti.

p vide Clnviumnbsp;ad 1$nbsp;quinti.

q per 16 Jexti.

I per 17 quinti.

Dec o^n c

Sifiti3xCD nbsp;nbsp;nbsp;^ del

dividatur utrinqueper a

C nbsp;nbsp;nbsp;hc Q dc

hc ATOO —2— .

«

Sifit^Aquot; f5 b X zo cd’^e d: dividatur utrinque per f5 ^

r nbsp;nbsp;nbsp;cdQ cd

30 nbsp;nbsp;nbsp;•

SifitrfATGO h bc e: dividatur utrinque per a

fit A'00

S\(it A X ZO b b b X-. *

auferatur utrinque bx eritque axbxzobb.nbsp;dividatur utrinque per^ — b

f. nbsp;nbsp;nbsp;bh

fit X CO -r .

a.b

Sï {\x. a X ZD b b b x: addatur utrinque b xinbsp;entcfitax bxzO bb.nbsp;dividatur utrinque per ^

fit a: 00 —rr

o

Si fit («A — a c ZO b X: addito utrinque a cnbsp;erit etx ZO bX a c.nbsp;auferatur utrinque ^ Anbsp;eritque xb xZO a c.nbsp;dividatur utrinque per lt;t — b

r

fit X X -r •

ab

Sifit^j.v — aczobx-ip-bc'. addito utrinque ac

mx. a xzob X -^-b c A s. auferatur utrinque bxnbsp;eritque axbx ZO bc Ac.

erit ut 4 ad b, ita b—x adA:. amp; componendo’quot;

ut 4 ^ ad ita b ad x.

erit “ ut 4 ad ^, ita a: ad a: •— c. amp; dividendo *

ut 4 — ^ad^, ita £¦ ad a;r. amp; per compofitionem rationisnbsp;contrariam ^nbsp;ut 4—^ ad 4, ita e ad x.

erit * ut 4 ad ita Aquot; c ad x—c. d amp; dividendo *¦nbsp;ut 4—^ ad ita z e ad a*—c.nbsp;Vbi liquet, etiamfi 4'“hic terminus proportionalis quantita-

tem


-ocr page 381-

fit co

DeMONSTRATIONIBVS. 3n diyidatur utrinquc per 4—b tem quxfitam x feorfim non ex-^c-^ac hibeat , ipfam tarnen ex tribusnbsp;' prioribus,quiquidemomnesfuntnbsp;cogniti, inveniri poflè. ld quodnbsp;fimiliterde prascedenti acfequen-ti formula aliis^ue eft intelligen-dum.

, At veró fi ipfa x quarto loco feparatim defideretur, licebit ui-terius fic argumentari.

«Haudfecus, cum lït ut 4 ad ^, ita X c ad a: — c,

erit invertendo “ nbsp;nbsp;nbsp;a per Cc-

roll, 4

ut ^ ad 4, ita X — c ad x c. ^uinti.

b quot;vide Clavium

C ad Z X. I'S

amp; per compofitionem ratio-nis contrariatn

ut^ad^-l-4, itax-Hinc cum4 — b-b.,

fint 3 magnitudines ab una parte,

amp; 2 c-X—c.......2 X

tres alias ab altera parte, quaebi-nas in eadem funt ratione, qua-rumque proportio eft ordinata: erunt ipfae quoque ' ex aequali-c pfr li.nbsp;tate in eadem ratione, hoe eft,nbsp;a—b ad ^ 4,ficut 2 c ad 2x feu c ad x. idperi^

qumU.

' c per 16

Sifit4c-H4xx^e—bx: additoutrinque^x

crit4c 4X ^xC0^c. auferatur utrinque 4 cnbsp;eritque 4 x b xCQ b c4 c.nbsp;dividatur utrinque per 4 ^

c nbsp;nbsp;nbsp;hcac

fit X X —tt •

Pars

erit' ut4ad^,itac—xadc x. lt;»,

amp; componendo ^ nbsp;nbsp;nbsp;fexti.

ut4H-^ad^, ita2cadc x. Rurfuscumfit

xut4ad^, itac—xadc x,

erit invertendo * nbsp;nbsp;nbsp;gperCo-

ut^ad4,itac xad£:—x.

amp; per converfionem rationis * h per Co-ut^ ad^— 4f^ac xad 2 x. roll.i^

ejuinti,

Yy nbsp;nbsp;nbsp;Hinc

-ocr page 382-

De

i feriZ fuinti.

k pfr 15 ^uinti.

^c:

addito utrinque ^ c erit (* X 4 cc CX)^.v.nbsp;auferatur utrinque lt;*xnbsp;eritque 4 c ^cCD^x—ax.nbsp;aperCor. dividatur utrinque per ^—a

1 per 16 Jêxii.nbsp;m per 17nbsp;quinti.

4quinti.

O vj'rfe Clayiumnbsp;ad 18nbsp;quinti.

ac ¦

fit

ZOX.

p per 12*

q per IS

quinti. r per 16nbsp;fexti.nbsp;sper iSnbsp;quinti.

Si fit 4 f'—4 xZDb X ^ c: addito utrinque 4 Xnbsp;crit 4 cZD bx ax bc.nbsp;auferatur utrinque b cnbsp;eritque ac—b cZObx a x.nbsp;t per Cor. dividatur utrinque per b

-bc

4 quinU.

U per Cor,. IJ quinti.

fit.

CONCINNAKDIS

Hinccum4 4-^—-—b.... b—4 fint 3 tnagnitudines ab una parte,

amp; 2 e-c x.... 2x

tres aliae ab altera parte, quas bins in eadem funt ratione, qua-rumque proportio cftordinata; erunt ipfs quoque' ex squalita-tein eadem ratione, hoe cft,

a-\rb ad b—4,ficut 2 c ad 2x feu e ad x.^

crit' ut ^ ad4,ita x c adx—c.»-amp; dividendo ut b—4 ad 4,ita 2 e ad x—c.nbsp;Rurfuscumfit

ernt^ad 4,itax-f-eadx-— erit invertendo quot;nbsp;ut4ad.^,itax — cadx-f-r.

Sc per compofitionem rationis contrariam'

ut 4 ad 4 ^,ita x—c ad 2 x.

Hinc cum b—4--4......4 ^gt;

fint 3 magnitudines ab una parte,

Sc 2 c-X—c. 2 X,

tresalisab altera parte, qus bins in eadem funt ratione, qua-rumque proportio cft ordinata: erunt ipfs quoque * ex aequalita-te in eadem ratione, hoe eft,nbsp;b—a ad 44-^,ficut 21 ad 2x feu c ad x.*

erit' ut b ad 4,ita c—x ad x c.» Sc eomponendo ’nbsp;ut b-^a ad 4,ita 2 c ad x-f-e.nbsp;Rurfuscumfit

«ut^ad4, itac—xadx-J-^', crit invertendo ‘nbsp;ut4ad itax-t-^ ade—x.nbsp;Sc per converfionem rationis *nbsp;ut 4 ad a-—by ita x-\~c ad 2 x.

Hinc

-ocr page 383-

Demon STRATioNiBvs. 35'5-

Hinc cum^ lt;ï--a.....

fint 3 magnitudinesab unapartc,

amp; 1 C——X-\‘C..... zx

tresalis ab altera parte, qusbi-na: ineadem funt ratione, qua-rumque proportie eftordinata; crunt ipfae quoque 'ex jequaIi-a/’«'iEnbsp;tate in eadem ratione, hoc eft,

b-k’a ad a—^,ficut 21 ad 2 a? feu c ad at. ‘ b /gt;«-15


erit ‘ut(«ad^,ita^—a: ad a?'—c.

Vnde concluditur c efle X Nam minor efle non poteft,nbsp;quoniam componendo foret, d/gt;er iSnbsp;ut4H-^ad ^,ita o ad xc. quodnbsp;eft abfurdum. Similiter majornbsp;efle nequit, quandoquidem pernbsp;compofitionem rationis con-trariam ' foret ut ad 4 ^,ita e videnbsp;c—X ad o. quod perindc abfur- Cjavwwnbsp;dum eft. Nec aliter fe res habet^f.!®

S\^iX.ax—-ac^bc’—'bx'. additoutrinque^cnbsp;erit^ATX bc-^-ac — bx.nbsp;addatur utrinque ^ a:nbsp;er itque a x-\-b xZD b c-\-a c.nbsp;dividatur utriiique per a-^bnbsp;fit a: X f.

in fequenti formula.

erit^ut4ad^,itaA?—cade — x.fpc ic Vnderurfus ut ante concludi- fai'-tur c efle x a;: cum nec majornbsp;nec minor efle polfit.

qumti.

Si fit ««c—axCD bxbe: addito utrinque axnbsp;erkaeCO ax-i-bxbe.nbsp;addatur utrinquenbsp;critqu e 4 c-^bc X ax-\-bx.

. dividatur utrinque per 4 ^ nbsp;nbsp;nbsp;^

fit £¦ X Aquot;.

Ty-

Yy


Cum igitur in refolvendo 'Problemate apparent, fitp-ponendo illud ipfum utjamfaBum, quopaBo quis argu-mentari pojjit, ut id quod in eo quaritur ex datis inve-niat; ritèmefaBurumjudicavi, Jiulterius hic oJJende-rem, qua rationepracedentium reduBionum vejiigiis in-fiftendoper ilia eadem retrogradi liceat, ad eequationes propojitas, quas ipfms ^roblematis conditiones adim-plere fuppono, Geometricè componendas.

-ocr page 384-

APeri6

(exti.


hferi6

fixti.


cperi6

¦fixti.


d ^er I ( fixti.


3j6 nbsp;nbsp;nbsp;De concinnandis

Typus veftigiorum, juxta quse aeqüationes fuperiüs reduftae ac refolutae rurfus componuntur, initiumnbsp;faciendo a fine reduélionis amp; per eadem vefti-gia regrediendo ; ad Compofitiones Geo-metricas ex calculo eruendas utilis.

Compofitiones Algebraic a nbsp;nbsp;nbsp;Compofitiones Geometrie £

is.x.axzobc. nbsp;nbsp;nbsp;exh “ a x “j;) b c.

multiplicetur utrinque per a facfto redangulo turn fub extremis

tumfubmediis

Sifuerit xZD— '• h.e.jfifitut^ad^jitac-adx^velpermutatim

lt;« ad c, ita bz.^ x:

£nax ^ bx'Xgt; cd. nbsp;nbsp;nbsp;erk * ax^bxzoed.

maltiplicetur utrinqueper^ f3 ^ faéio reftangulo turn fub extremis turn fab mediis

Si fit X 00 nbsp;nbsp;nbsp;: h.e.j.fi fit ut ^ f3nbsp;nbsp;nbsp;nbsp;d ad x’, vel permuta*

tim 4 f3 ^ addyiiz ezix:

fit(J a:00^f f3 nbsp;nbsp;nbsp;* axCO b cf^dc.

multiplicetur atrinque per lt;t fado redangulo turn fub extremis turn fub mediis

Si fit a: 00 —5— :h.e.,fifitutlt;iad^ f3 «^jitacadArjvelpermu-

tatim d ad lt;7, ita ^ f3 ad AT:


fit^A- f3 bxCOed f3 ed. multiplicetur per b


exit^axf^bxCOcdf^ed. fado rcdangulo turn fub extremisnbsp;turn fub mediis


Si fit X 00 —-§4—: h. e., fi fit ut 4 f3 ^ ad c f3 ita lt;a! ad a: j vel


aSb


permutatim 4 f3 ^ ad a!, ita c nbsp;nbsp;nbsp;e ad a:.:


c pet 16 fixti.

•CC.

ftxax-XibbCC. nbsp;nbsp;nbsp;erit*4Aroo^^-

multiplicetur utrinque per 4 fado rcdangulo turn fub extremis turn fub mediis

SifitATOO nbsp;nbsp;nbsp;: h.e.,fifitut4ad^-t-£’,ita^—cadAtj vel

a

permutatim a ad ^—c,ita ^ 4- a: ad :

- * - ,

-ocr page 385-

Demonstration! BV s. 35’7

^taxZDbh-^-bx. nbsp;nbsp;nbsp;ax “X) b bh X.nbsp;nbsp;nbsp;nbsp;£feri6

addatur utrinque bx nbsp;nbsp;nbsp;idefl:,reducendoproportionem'^^’'quot;'

adsqualitatem

eritquc^a:—bxzobb. nbsp;nbsp;nbsp;VLt.aidb, ita b xadx

multiplicecurutrinqucper^--^ nbsp;nbsp;nbsp;eritcomponendo ^nbsp;nbsp;nbsp;nbsp;gpfrnbsp;nbsp;nbsp;nbsp;i*

^ jy nbsp;nbsp;nbsp;quinti,

SifitATX hoe eft.fi fit ut lt;* — ^ ad^jita^adarr t nbsp;nbsp;nbsp;vtfupraad

“¦ — quot; nbsp;nbsp;nbsp;notam t

ftt^AT00 bbbx. auferatur utrinque bx

ent’’axZObbb x. nbsp;nbsp;nbsp;hpcriS

id eft, reducendo proportionetn-^’'*'quot; ad a:qualitatemnbsp;critque«ïa; ^;c00 bb.nbsp;nbsp;nbsp;nbsp;utlt;Jad^,ita^—xadx

multiplicetur utrinque per (* ^ nbsp;nbsp;nbsp;eritdividendo ‘nbsp;nbsp;nbsp;nbsp;iper iy

SifitArOO a^'b ' ^^^^^^^^’•^^^^'^~i~‘badb,ita.bsidx: nbsp;nbsp;nbsp;^

fitax'—'acx bx. auferatur utrinque a c

eritque axxbx-\-Ac. addatur utrinque bxnbsp;crit/i a:—bxx ac.nbsp;va


erit*'lt;*A:—acXibx. nbsp;nbsp;nbsp;kperib

id eft, reducendo proportionem/^^*'* ad aequalitatemnbsp;utiïad^, itaAradA? — c.

amp;componendo' ' l pens ut4 — bzdby ita c ad a: — c.


tn\.axbxzoac. nbsp;nbsp;nbsp;aiay m c zaxc. 'i-quot;

lultiplicato utrinque per 4—b erit per divifionem rationis .

contrariam ^ nbsp;nbsp;nbsp;m


1 vfde Clayium

ad 17 ^uinti.

ent” axaczobx-^bc. nbsp;nbsp;nbsp;npene

id eft , reducendo propottionem fixti. ad stqualitatem,nbsp;ut 1* ad ^, ita AT c ad AT —cnbsp;amp; componendo •nbsp;ut4 — ba.db, ha, z c zd Xc.nbsp;(itax—AcXgt;bx be. vel, fumptis confequentiumnbsp;auferatur utrinque lt;ï c.nbsp;nbsp;nbsp;nbsp;miftibus , ^nbsp;nbsp;nbsp;nbsp;ad Z2.

eritque 4 ArOO^A: ^c 4e. nbsp;nbsp;nbsp;ut4—^ad 2^,ita 2cad 2a;—zc.qumtl.

addatur utrinque ^a; nbsp;nbsp;nbsp;id eft , per divifionem rationis


SifitATOO nbsp;nbsp;nbsp;hoe eft,fi fit ut lt;ï — ^adlt;ï, itacadAr:


critAA;—bxXtbc-^Ac.


per

contrariam,

yy 3


ad 17

mui-


-ocr page 386-

tfer 15


358 De CONCINNA.NDIS

multiplicato ütrinque per a—h ut 4 — ^ ad ^ nbsp;nbsp;nbsp;2 c ad z ar.

eritetiatn '

hoceft, fi fitutrf—


Si fit a: 00


s pef 16 ftxti.


t ^er 17 quinti.

U yide Claviumnbsp;ad 12nbsp;quiirti.

X vide

Clavium

ad iS

quinti.

yferii

quinti.

% per 16 fexti.


. ütac^-axco bcbx, auferatur utrinque bxnbsp;eritque ac-^a x-^b xzobc.nbsp;addatur utrinque avnbsp;eritlt;aA’ ^x bo benc.nbsp;multiplicato utrinque per a-^^b


erit' ac-^axPXi bcbx. id eft.reducendo proportioncmnbsp;ad «qualitatem,nbsp;ut a ad by itac—xadf-f-x,nbsp;amp; dividendo *

ut(ï-4-^ad^, itazcad lt;r x. vel, fumptisconfequentiumfe-miflibus, •

ut4 ^ad2^,itaacadz c 2x. id clK per compofitionem ratio*»,nbsp;nis contrariam, *nbsp;ut a hz-Ab — 4,ita z c ad 2 x.nbsp;eritetiam ^


Si fit X X


hc—ac


: hoceft,fifitut4-4-^ad^—(*,itacadx;


a per 18 quinü.

b vide

Claviim

ad 22

quinli.

C-vide

Clavium

ad IJ

quiuti,

d /gt;o' 15

quinli.


fit4Xnf-4cX^X — bc. auferatur utrinque b c.

eritque 4 x 4 c-\-b cZObx. addatur utrinque«xnbsp;eritiïÉ' ^c X bx—4X.nbsp;multiplicato utrinque per b—a


erit 4x rfcX ^x — bc. id eft,reducendo proportioncmnbsp;ad tequalitatem,nbsp;ut b ad 4, ita X f ad X—c,

amp; componendo * ut b—4 ad4, itaz cadx—c.nbsp;vel, fumptis confequentium fe-milïibus, ‘

ut b—a ad 24,ita ac ad 2x-—2 c. id eft , per divifionem rationisnbsp;contrariam, ‘

ut^—4ad4 ^,ita 2 cad 2X. eritetiam^



-ocr page 387-

De monstrationibvs. 359

eric ' ACax zo bxb c. nbsp;nbsp;nbsp;eper is

id eft, reducendo proportionem/^*^' ad asqualitatemnbsp;Ut^ad4,itac—xzdx-{~c.

Sc dividendo ^ nbsp;nbsp;nbsp;fperij

ut ^ ad 4, ita 2 £• ad Ar c.


?ix.ac—a x^Xibx-^bc', auferatur utrinqiie a x

vel, nbsp;nbsp;nbsp;confequentium fe-

miflibus, * nbsp;nbsp;nbsp;g -vide

ut b-^-a ad 2 lt;*,ita 2 c ad 2 A- 2 c. clarium eritque«*cao^Ar lt;«Ar ^c. id eft, per compofitionem ratio-addaturutrinquenbsp;nbsp;nbsp;nbsp;nis contrariam, *nbsp;nbsp;nbsp;nbsp;livide

ad iS

^ nbsp;nbsp;nbsp;-nbsp;nbsp;nbsp;nbsp;-nbsp;nbsp;nbsp;nbsp;quinti.

Si fit CO Ar:hoceft,fifitut^ lt;iadlt;j —^,.itacadA:; M

crit4c—bcODbx-i^ax. nbsp;nbsp;nbsp;Ut^r. ^ad4-—by ita2 c ad2 x.

multiplicato utrinque per b a erit etiam '

quinti.

b -f» i

fit^A;—acO^bobx. auferatur utrinque a cnbsp;eritque lt;« AT CD ^ c-4-lt;ï c • ^ rt,nbsp;auferatur utrinque b xnbsp;exvcax-^-b xZDb c-^-ac.nbsp;multiplicato utrinque per

Si fit AT CO c: feu,quod idem eft,{i at fit ad r,ficut lt;J -J- ^ ad A^b:

fit4«'—lt;4 a: co ^a: — bc. auferatur utrinque 4 a:nbsp;eritque ««cco^at ^a: —nbsp;auferatur utrinque ^ cnbsp;erit lt;« c ^ c X «lt; at ^ AT.nbsp;multiplicato utrinque per 4 -^b

Si fit c X AT: feu,quod idem eft,fi c fit ad A:,ficut 4 -f» ^ ad 4-|»^: -

Guminduabusprascedentibus formulis non occurrat qua via per proportionales , ut ante , ad atquationes priores pervenia-tur : licebit per «qualitatem prccedere , tequalia per aequalianbsp;multiplicando, ac deinde ab squalibus xqualia auferendo, omnirnbsp;no at in Compofitionibus hifce Algebraïcis faólum eft.

P Bi

-ocr page 388-

300

De CONCINNANDIS

Problem A.

Datam reftam A B, utcunque feftam in C, rurfuS fecare in D; ita iit reélangulum fub A D, D C compre-henfum fit sequale quadrate ex D B.

Series Analyfeos five Refolutionis.

Suppofito P roblemate ut jam faólo, vocoA C. anbsp;C B. ^

amp; C D. j eritque AD30(* .v, amp; DBoo^—-x

iB

-.1

Deinde ut habcatur xquatio, Multiplico AD. a Xnbsp;perDCfeuDE.nbsp;nbsp;nbsp;nbsp;x

Etfit reftangulum AD E t.ax xx.

Similiter multiplico D B. hx perDBfeuBG. ^— xnbsp;bx-\-xxnbsp;bbbx

EtfitquadratumD BGH. nbsp;nbsp;nbsp;—ibx-\-xx.

V ndc tabs exurgit sequatio

ax xxzobbibx-{-xx.

Ad quam reducendam tollatur utrinque x at, eritque^xod*^^— i bx.

Deinde transferatur 2 bx ad alteram partem , ut incognltx quantitates ab una parte habeantur, amp; cognitat ab altera parte,nbsp;SiHtax z ifxjDbb.

Cujus

-ocr page 389-

Demonstration iBvs.

Cuiusutraqueparsfidividatur per a zégt;,

¦ nbsp;nbsp;nbsp;hb

invenieturAT GO

-j^Yb' Hoceft, refoluta squalitatc

in proportionem, eritut a zlf ndh, ita ^ adar. ld quod docet, ad fecandam A B in D, qualis requiritur, pro-ducendam effe A B ad I, ita ut BI fit aqualis B C; ac deinde adnbsp;AI amp; IB vel BC inveniendam efie ^“'quot;proportionalem, hoenbsp;eft, ut A I fit ad IB vel B C, ficut B C ad C D.

Vtautempateatdemonftratio, repetantur Analyfeos veftigia. Si enim per hsc ipfa regrediamur, incipiendo ab ejus fine amp; defi-nendo ubiilla initium fumpfit, inventa fimul erit via a dato feunbsp;conceflb perveniendi ad qusefitum. In quem igitur finem binasnbsp;fequentes compofitiones, quarum altera Algebi'jc, altera Geometrie genuina eft , ob oculos ponere vifum luit, adhibita utriuf-que calculi interpretatione five ad figuram relatione.

Compojitio Algebrdica. nbsp;nbsp;nbsp;Compofitio Geometrie a.

Finis Compojitionis.

i=]AD,CDvelADEF

amp;fit^A;-l-;vArOO ? DB velDBGH.

bbz bx-\-XX.

? C D vel D K Addatur utrinque a; A-,

cziAC, CD eritque' axZD

(?DB—? C D vel D K) i.e. ^ *nbsp;nbsp;nbsp;nbsp;cziCBK

bbz bx.

cr]CI,CDvel'CGCDI-|.^CD Auferatur utrinque 2 bx,

?AI,GD ?IBvelBC erit^ ax-^\bx '::D bb.

Pm II.

? AD, CDvelADEF Et fit, per^.-L^*gt; ax-^xxZD

a per 5 Jècundi.

? DBvelDBGH. bbzbx-\~xx. fft6. i*gt;

? C D vel D K Addatur utrinque xx

ent,peri6.6‘- axODbbzbx. ld eft, reduöa proportione adnbsp;equalitatem,

AC CB BK KDvelCD i\tazdb,\x.zbzxzdx.

Et, iumptis conlequentuimfe- d per i

miffibus, yide Claviumad zi jquot;- Jècundi.

AC Cl BK KC

niazdz byiXdibixadix. e prr j Vnde dividendo erit,po' 17nbsp;AI I C B C 2 C D vel CKnbsp;ut4 2^ad2^,ita^ ad 2 A’. fpcriynbsp;Zz

-ocr page 390-

jöx De concinnandis

ideftj redudaproportione five,fumptisconfequentium du-ad cequalitateoi, nbsp;nbsp;nbsp;plis, Clayitmad ii. 5''-

AI IB BC CD

Ex conftrudione eft , utlt;« 3^ad igt;, ita ^ ad x.

Principium Compojltionis.

Adaperta itaque tum ad Conftruótionem tum ad Demonftra-tionem via, licebit Problema conftruere atque dupliciter demon-ftrare, ucfequitur.

ConjiruHio.

Produftii A B ad I, donee BI fit sequalis B C. fiat ut AI ad IB vel B C , ita B C ad C D: dico reftangiilumnbsp;A D C feu A D E F quadrato D B feu D B G H jequalenbsp;elTe.

Demonjlratio.

Cum enimex conftruótione AI fit ad IB velBC, utBCad cjamp;friy CD: erit ^ reélangulum fiib extremis AI, CD , id eft, *re-hfer I lt;ftangulum fub A C, C D iina cum reöangulo fub CI, C D, te-feemdi. quale quadrato medi^ I B vel B C. A quibus fi commune aufe-

Hr

iB

C Dj K

'•*E

iper 5

fecundi,

},SJ.

ratur reclangulum fub CI, C D: erit reliquum reflangulum fub A C, C D squale B C quadrato, dempto eidem reótangulo fubnbsp;Cl, CD, ideft, ‘ redangulo CDI una cum quadrato CD.nbsp;At cum dempto CDI redangulo a quadrato C B vel B I* re-linquatur quadratum D B : patet didum redangulum A C Dnbsp;quadrato DB squale efle minus quadrato CD. HinGcum,fu-

mendo

-ocr page 391-

Demonstrationibvs. 363

mendo CD amp; DK sequales, quadratum DB minus quadrato 1;^^^ CD vel DK' £Equale lic reöangulo CBK; manifcllumeft, liW(. *nbsp;Kqualibushifcereótangulis ACD amp; CBKaddatur communenbsp;quadratum CD vel DK, etiam totum toti sqnale effe, id eft «¦«'po' jnbsp;rcdlangulum A D C feu A D E F ipfi D B quadrato feuD B G H.

Quod crat faciendum.

VelJIc-,

Cum ex conftrucftione fit ut AI ad IB, ita B C ad C D : erit quoque, fumptis confequentium duplis, quot; ut AI ad I C , ita B C n v/'*nbsp;ad 2 C D feu C K; amp; dividendo ' ut A C ad CI, ita B K ad K C;nbsp;id eft, fumptis confequentium femiffibus J ut A C ad C B, 'mquinti.nbsp;BKadKD velCD. Aïquale-igitur eft quot;gt; rclt;Sangulumfubextre-o per 17nbsp;mis A C, C D reélangulo fub mediis C B, B K. Quibus fi adda-tur commune quadratum CDvelD K, erit amp; totum totisqua-c/^^f,,^nbsp;kjideft, ^ reétangulum AD C feuADEF ipfiquadrato DBaJ ünbsp;feu D B G H ‘. Quod erat faciendum.

q per ifi

Problem A. nbsp;nbsp;nbsp;-fquot;;; ^

Data reda A B utcunque fefti in C , eredl^ue exf 0 ejnstermino Bfuperipfa perpendiculari indefinita B Dnbsp;ex altero ejus termino A reftam lineam ducere A D,nbsp;huic occurrentem in D; ita ut ipfa tequalis fit reftisnbsp;DB, B C fimulfumptis.

Series Analyfeos.

Ponatur faéium quod quaeritur,

litque A B 03 ^

C B 30 ^

amp; BD OOx;eritque AD 30^ AT.

Hinc cum angulus adB fit reöus , erit *'quadra-a ^6^47nbsp;turn ex A D jcquale binisf’^quot;”*'nbsp;quadratis ex A B amp; B D.

Zz 2 nbsp;nbsp;nbsp;Vnde

-ocr page 392-

364 De concinnandis

Vnde talis refuhat sequatio

?AD gAB dBD bb z bx-\-xxZDai^ xx.

Ad quam reducendam, tollatur utrinquï atat, eritque bb ibxZDda.

Deinde transferatur ^ ^ ad alteram partem, ut incognita quan-titas ab una parte habeatur amp; reliqux ab altera parte f amp; fit zbxZDaabb.

Cujus utraque pars fi dividaturper z by

obtinebitur x 30 nbsp;nbsp;nbsp;. Hoe eftjrefolutatequalitate

inproportionem, erit ut z ^ ad -H ita «—^adAr.

Quodipfumdocet, adProblemalioc folvendum, proutBE in direólum ipfius A B fumpta eft squalis B C, opus tantum eflc,nbsp;ad C E, A E , amp; A C in venire 4™quot; proportionalem B D.

Ad inveniendam autem demonftrationem, fiat repetitio vefti-giorum Analyfeos, incipiendo ab cjusfine amp;pereadem veftigia progrediendoufquead ipfiusinitiumj itavidelicet, ut quod innbsp;Analyfi feu Refolutione addendum prjccipitur, id in Synthefi feunbsp;Compofitione fubtrahatur, amp; contra: cum Analyfis amp; Synthefisnbsp;diredè omnino fibi invicem opponantur.

Finis Compojïtionis.

frimi eper 47?-cundi.

Vnde amp; ipfie reamp;.x F D amp; A D. jEqualiaigiturfuntGFD amp;GAD.nbsp;hpn47 gFB zoFBD gBD.vcIgFD*. GAB GBDjYcIgAD'.nbsp;^t£i.Kbb-\~zbx xx CO aa xx.

? BD

d per 6 fe~ ciindi.

Rurfusaddaturutrinque xx,

? FB 2CZ3FBD GAB^. eritque ^^4-2 co aa.

C per 16 fxti.

? FBvelBC Addatur utrinque b bynbsp;oCE, BDfeu2oFBD oEAC.nbsp;erit * z bx 20nbsp;nbsp;nbsp;nbsp;au—bb

id eft.

-ocr page 393-

DeMONSTRATIONIbVS. 3(55-id eft , reduöa proportione ad £Equali:atem , fumptatjuc FB aequaliBC,

CE AE AC BD

Ex conftru(ftione eftut 2 ^ ad ^ ita 4—b ad

Principium Compojitionis.

Invcnta igitur turn Conftrudione turn Compofitione five De-monftratione, poterit Problema , neglefto jam artificio, quo utraque fuit inycftigata,in hunc modum conftrui atque componi.

ConJiru£iio.

Produfta A B ad E, ut B E fit xqualis B C: fiat ut C E ad A E, ita ACadBD, jungaturque AD. Dicohanc ipfis DB, BCnbsp;fimul fumptis sequalem efle.

T)emonflraUo.

Etenim produfta D B adF, ita ut B F fit jeqiialis B C, quo-

niam per conftruélionem C E eft ad A E, ficut A Cnbsp;ad B D : erit ^ redangu- Cpenfnbsp;lum fub extremis C Enbsp;BD, id eft, duplum rc-(Sangulum F B D, sequalenbsp;reótangulo fub mediis E A,

A C. Quibus fi addatur commune quadratum exnbsp;Inbsp;nbsp;nbsp;nbsp;FB vel BC , erit etiam

iF nbsp;nbsp;nbsp;quadratum F B una cum

duplo reftangulo F B D

sequale quadrato ex A B^. Quibus fi rurfus addatur communegfj.^y?-quadratumexB D ; eruntquoquebinaquadrataex FB, BD fi-^^quot; mill cum duplo reiftangulo F B D, id eft *, quadratum totiusFD,nbsp;aequalia binis quadratis exAB, BD, ideft ', squalequadratonbsp;ex AD. Vnde amp; ipfae reflse FD amp; AD squaleserunt. Flinc^^^wi.nbsp;cum F D sequalis fit ipfis D B, B C fimul fumptis, erit etiam A Dnbsp;ipfis D B, B C fimul fumptis sequalis. Quod erat faciendum.

Zz 3

Theow

-ocr page 394-

306

De concinnandis

Theorema.

Si in quadrante circuli ABC fumatur arcus quilibet B D minor quam 45- gr. cujus duplus fit B E, eorumquenbsp;tangentes B F, B G eric ut quadratum radii A B minusnbsp;quadrato B F ad duplumquadrati A B, ita B F ad B G.

a nbsp;nbsp;nbsp;Series Analyfeos.

Efto ABxlt;*

B Fcoar

B GoD^jeritque F GqOj—x

H nbsp;nbsp;nbsp;amp;AGx?:.

Quoniam itaquearcus BE ipfius BDduplusponitur, aeproindean-gulus BAG duplusanguli BAF:nbsp;erit angulus ad A in triangulo ABGnbsp;refla A F bifariam fedius.

Vnde “ erit

ut FG ad BF, ita AG ad A B


A per 5 fexti.


y—


X-


Ideoque ‘ ? B F, A G squalc a'” F G, A B xz COnbsp;nbsp;nbsp;nbsp;ayax.

div. utnnqueperar


b per 16 fexti.


ay-


fit


20


Hinc duaa utraque parte in fe quadrate,

a a JJ CDzz.

primi.

. nbsp;nbsp;nbsp;aayy^aaxy aaxx

eutzzeo-^-^- 20

mult.utrinqueperxx ggyyzaaxy-^aaxxco aaxx-^xxjy toll.utnnque^(«xa;nbsp;nbsp;nbsp;nbsp;aayylaaxy COx xyy

d^iv. utrinqueper;- nbsp;nbsp;nbsp;aay-zaax^xxynbsp;nbsp;nbsp;nbsp;'

add. utnnque 2 aax-^---

,, r nbsp;nbsp;nbsp;aaypozaax xXy

toll, utnnque X ary-^

... nbsp;nbsp;nbsp;aayxxyCD'i-aax

r nbsp;nbsp;nbsp;xaax

fit7 20 - .

?AB—DBF 2DAB BF BG Hoc eft, erittitialt;*—xxa.dzaay itaA;ad7. Vtproponebatur.

De-

div. utnnque per lt;i 4 —xx -------

-ocr page 395-

Demon STRATiONiBvs. 367

Demonftrationis feries eodemmodo fchabetquo Analyfeos, cum utriufque vcftigia confentiant, quibus ab bypotbeli ad qus-fiti concluboncm perducimur. Vti bic videre eft.

CPfrj

jextt.

Etenimcum' fit ut FG adBF, itaAG ad AB:

y—-X-a./ A

entquoque ^

utaFGadDBFjitaDAGfeuD AB DBGadDAB j/yzxy xx-XX——z.'Z} ideft, aa jy /


d per 16 fixti.


amp; dividendo * utnFG — nBFvelFH,nbsp;ideftjCnBGH^' adnBF, itanBG adnABnbsp;yjzxy‘- XX -yj / a a,

permutandoque ^

utaBGHad OBG, vel* utHG ad G B,ita DBF ad ? AB

j — 2 a;--j - xx! aa.

Ideft, invertendo amp; per converfionem rationis ’, ut ? A B ad ? A B ¦— ? B F, ita G B ad B Hnbsp;aa -—aaxx-- y / zx.

amp; duplatis antecedentibus ^ convertendoquc utDAB — nEFadiDA B,ita B H ad 2 G B feu B F ad B G'nbsp;a a-—XX -2 aa ----- x / y.

cper 17 ^uinii.

f per 6 fecundi.

g per IS quinti.nbsp;h per Inbsp;[exti.

i per Cor. 4 quinti,nbsp;O' pernbsp;Cor. 19nbsp;quinti,nbsp;k videnbsp;Claviumnbsp;ad zinbsp;quinti.

¦ nbsp;nbsp;nbsp;Quod crat oftendendum.

Quod fiautem Algebras ignaris five in inveniendi arte impe-^ nbsp;nbsp;nbsp;5

rltis ipfa demonftratio fit exbibenda, poteriteaprstermilfisjam^*^^”*^’ hifee veftigiis fic adbiberi.

Sumatur F H aequalis F B. Gum igitur in triangulo A B G an-gulusad AredaAFbifariamfedtuslit, erit’” ut F GadBF, ita^j^^ ^ A G a'd A B. Sed cum linearum proportionalium etiam propor-tionalia fint quadrata, erit amp; ” ut quadratum FG adquadratum^^^J*^^^nbsp;BF, itaquadratum AG, ideft,perfummaquadrato-operi7nbsp;rum A B, B G, ad quadratum A B. Et dividendo * ut quadratum ?«quot;»'•nbsp;EG minus quadrato BF vel FH, id eft ^ redangulumnbsp;adquadratumBF, ita quadratum B G ad quadratum AB; per-q|,o.j,;nbsp;mutandoque * ut rectangulam B G H ad quadratum B G feu ¦¦ ut quinti.nbsp;H G ad G B, ita quadratum B F ad quadratum A B. Hoc eft,nbsp;nbsp;nbsp;nbsp;*

-ocr page 396-

368 De concinnandis

liperCor. invcrtendo amp; per converfioncm rationis’, utquadratum ABad ^ per ’ qwadratum A B minus quadrato B F, ita G B ad B H; amp; dupla-Cor.19 tisantecedentibus ' convertendoque, utquadratiim AB minusnbsp;quintl. quadrato B F ad duplum quadrati A B, ita B H ad duplum ipfiusnbsp;tyideCk- Q J3» gp ^d ÉG. Quoderatdemonftrandum.

z^qumtL

U per nbsp;nbsp;nbsp;_nbsp;nbsp;nbsp;nbsp;_nbsp;nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;.

quinti. Si, Tangenscujuflibetarcüsminorisqiiamifi^gr. du-^_^catiir in duplum ^adratum Radii; d ^adratoRadti ^^auferatur Tangentis quadratum-, Illudprodu£fum divi-, daturper hoe rejiduum-. ^lotus er it Tangens areüs dupli.

Theorema höc a Clariffimo viro D. loanne Pellio excogitatum atqueingeniosè adhibitum pluribus modis demonftratum repe-ritur in tradam ejusde controverfiis, circa verana circulimen-furam, inter ipfum amp; Clar. virumD. Chriftianum SeveriniLon-»nbsp;gomontannm orcis, acanno lö'qy in lucemeditis.

Theorema,

Si fuerit triangulum ABC, cujus angulus ad B re-^la B D bifariam fit divifus, dc ex B C abfcindatur B E jequalis A B, jungaturque A E, fecans B D in F : dico,nbsp;fi agatur E G parallela A C , occurrens ipfi B D in G,nbsp;efTe ut B G ad B D, ita A D ad D C, amp; A B ad B C;nbsp;nee non D C bis efle ad excefTum; quo D.C fuperatnbsp;A D, ficut B D ad D F.

Series Analyfeos.

Efto B D 00 ^

AD 3D c .

D C 007 amp; D F 33 c.

Quoniam itaque trian'* gulorum ABF ,E BFan-guli ad B ex hypothefi funtnbsp;xquales, nee non latera AB, BFamp;r EB,BF, quïe ipl'os compre-^ hendunt, squalia: eruntamp; quot; anguji ad F jequalcs, ideft redi,

ballf»

-ocr page 397-

Demonstrationibvs. 369

bafisque AF bafi FE squalis. Porró cum ‘ propter parallelas b/.fvi, A C, G E anguli D A F,F £ G in triangulis A F D,F G E arqua-^''quot;quot;'-les fint, ut amp; ‘ an^ub ad verticcm A F D amp; G F E, latusque A F c po-1 ynbsp;laceriF E, utoftenlum eft: erunt quoque ‘‘ reliqua latera Anbsp;D F reliquis lateribus E G , G F xqualia. Hinc cum' propter fi- fnbsp;militudincm triangulorum B G E, B D C, B G fit ad G E, id eft, e jgt;crCor.nbsp;A D, iicut B D ad D C ; nee non B G ad B E , id eft A B ficutnbsp;BDadBC: critquoque^ permutando B G ad BD, ficutADfprr isnbsp;ad D C, amp; A B ad B C. Quod eft primiim.nbsp;nbsp;nbsp;nbsp;^uinii.

Castcrum D C bis efle ad exceflum,quo D C fuperat A D,ficut B D ad D F: ita patet.

Eftcnim,utBG ad BD, itaADadD C ^—zz.—————c / ƒ.

g fcrii jcxti.

Ideoqiie* CU B G,D C od c:;''’ B D,A D. hj•ijK.'X) hc.

hyX) ^ nbsp;nbsp;nbsp; b o

bybeX) z yz.

add. utrinque

hyh c

fit

toll, utrinque div. utrinque per zy

ZO z. Hoe eft, erlt at BD DF

ly

2D C DC—AD zydiiyc, ita ad s:. Quod eft fecundum.

Veletiam, hoemodo'.

Etenimcumfit

ut BG ad BDjitaADadD C nbsp;nbsp;nbsp;'*

b2^.-b--'C / y.

h per Cor,

4

i per Cor. 12

}C 'Zr iele

crit invertendo *

ut D C ad A D, ita B D ad B G

y - c—---b / bZz-

amp; per converfionem rationis'

ut D C ad D C — A E), ita B D ad D G

y---b / nbsp;nbsp;nbsp;22:.

ut 2D CadD C zy

id eft, duplatis antecedentibus, ^

AD,ita 2BD ad DG feu B D ad DF Ckvmm

y^C------- b /

^ Aaa nbsp;nbsp;nbsp;Ex^quot;quot;quot;-

Pars l7.

-ocr page 398-

a fff 15 fecundi.


JL/t. CONUiJNiNAJNUlO

Ex his tacile eft, cognitis A D, D B, amp; D C, invenife D F.

Si enim, exempli gratia, AD lit 39, DB45, amp; DC325* fiat ut iDCö^joadDC — AD iSö^jitaDB^jjadDF ipj.

MA.


The


ORE


lifdem pofitis , dico reftangulum A D C una cum quadrato D B afquale effe reélangulo ABC.

Series Analyfeos.

Efto A B OD BD 33 ^ ¦

AD 30 S’

B C 30 .V ¦ D C 30/

amp; D F 30 x:.

E tenim cum ^ 2 nbsp;nbsp;nbsp;DFfitoo OAD-f-DDB —— Q A B,,

ideft, 2^?. nbsp;nbsp;nbsp;30nbsp;nbsp;nbsp;nbsp;cc bbaa'.

C C nbsp;nbsp;nbsp;b -


erit,»dividendoutrinqueper 2 nbsp;nbsp;nbsp;5.C10


• aa


Vnde cum per antec.Theorema inventum quoqjfit nbsp;nbsp;nbsp;00


. cc-i-bb-'aa^ by—bc

ent nbsp;nbsp;nbsp;—— 00nbsp;nbsp;nbsp;nbsp;-

b nbsp;nbsp;nbsp;y


divifo utroque denomina-


Ex demonftratis in antec.'


ritL'iicati’o iacmcem ccj bby-aajoybby-bbc Theoremate vel

add.umnquelt;.^ ^ nbsp;nbsp;nbsp;utAD adDC.itaAB adBC

toll.utrinqueiSji --—¦— --^ nbsp;nbsp;nbsp;/nbsp;nbsp;nbsp;nbsp;“* /

¦ bbc nbsp;nbsp;nbsp;acproindef^i^/Aii


add.utrinqueüc ¦ loco dji fubftit. c a; ¦


ccy 30 tt ay-


ccy b b e ZO aay


[loADjB CoocoAB.DC 'cx 30nbsp;nbsp;nbsp;nbsp;lt;*/•


div.utiinque per c


c cy b b c 00 lt;tc x


?ADC nDB coABC Et fit cy-k- b b 30 a x. Quod erat propofituna.

Quo autem pafto in adaequatione hac réfolvenda argumen-tandumfit, utfequendo veftigia allatae redudlionis, qusobfu-periorem multiplicationem per crucem propriè Algebraïea eft,

* qux-


-ocr page 399-

Demonstrationibvs. 371

qasefitum Theorematis Geometricc concIudatUT, fequens ter-minorum difpofitiodocebit.

Ex prïcedetiti Theofemate cft

uczDC ad D C —AD,itaBDadDF

XJ----b /

acpromde‘ 2CD CDF sequabCDBD C—CD ADB nbsp;nbsp;nbsp;bfo-is

» zjz CO nbsp;nbsp;nbsp;bybc.

b--

fexti.

Deinde' eft, ut B D ad D C, ita 2 cd B D F ad 2 CD C D F. af- c pn i s

fumpta fc. com. alt. 2 D F, id cft, 2 nbsp;nbsp;nbsp;,

Tj- nbsp;nbsp;nbsp;’ d per 1^-

Hinc CUm nbsp;nbsp;nbsp;fecundi.

iCDBDF aequ.aAD DDB-D AB,amp; «2CdCDF a;qu.tD3BDC-CDADB: ïbz CDnbsp;nbsp;nbsp;nbsp;cc bbaa, amp; zyz CO bygt;bc’.

critutBD adD C, feu ' OBDadcDBDC, nbsp;nbsp;nbsp;fafflim-

b b —quot;—___bj nbsp;nbsp;nbsp;ptacorn.

ita DAD-fdDE—DAB ad cdBD C—cdADB. cc-\-bba a---bybc

zyz.

altit.B D, id eft, b.

fperi9 quinti.

ideoquc

amp; rdiq.DAB—? AD ad rcl.CDADB,ut totum ad totumfeu BD ad DC.

a a—'CC —7—-b c ---^ l y-

Factie htc ejfet qutejltum Fropojittonis concludere^re-•üocando hanc frofortionem ad aqualitatem, amp; deinde in locum ay JubJiituendo c x. Sed quoniam fic adfoUdanbsp;afcenditur, dequibus in fofterioribus Flementorumli-bris agitur, qui ob difficultatem fuam magisfrateririnbsp;qudm proFlementis Geometrice addifci Jolent, foteri-mus üfdem fepofitis in auafiti xonclufionem ficulteriüsnbsp;argument ar i.

ptacem.

Sed utB D eft adD C,itaquoque nbsp;nbsp;nbsp;? A D B adczi A D C; altit.AD*

'--ƒ - bc ! nbsp;nbsp;nbsp;c,;

amp;utBD ad AD, itaquoquceft*CD ADBad pADj nbsp;nbsp;nbsp;pta com.

U nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;/ . /nbsp;nbsp;nbsp;nbsp;altit.A D

b - ---bc /


? BDadaADBfeu^^ad^c.^afu”-

pta com.

A aa z 'Eriint BD

-ocr page 400-

37^ nbsp;nbsp;nbsp;De concinnandis

Eruntitaque DAB—?AD,cz]ADBjamp; DAD tres magnitudinès

a a — cc~=—bc.......cc abuaa parte;

amp; ? BDjCZi ADB,amp; nn APC tresalis abaltera bb.......bc.........cparte, qute binae


k per 15


1 per 18 quinti.


lumpta: in ea-dem funt ratio-ne , quarum-quot; nbsp;nbsp;nbsp;que proportio

eft perturbata:

quareeti^ini exjequalitateproportionalcserunt, id eftjD A B —. ? A D ad ? A DjficutD B D ad ? ADC.nbsp;a acc———cc---bb / cy.

Etcomponendo


? AB adaAD,ficutnBD c:ADCada AD C aa--cc----bb cj / cy.


m per 16 qiiinlL'


n per I Jexü.nbsp;reliftinbsp;fc. com.nbsp;altit. A Dnbsp;feu c.


Permutandoquc ^

?ABadnBD a A D Cjficut? AD ada AD Cfeu ali- b b c^-:—^— cc ! cy.


AD adD Cjideftjcad^ “ Sedut A D adD C,ita” eftquoqiie A B ad B C,feu^, ? A Bnbsp;c —^—y ——^^^— a /


.V.


o per antec.nbsp;Theorema vel 3nbsp;fexti.nbsp;p alTum-pta com.nbsp;altit. ABnbsp;feu a.nbsp;qper9


ado ABC, id eft', anadax. Vndeerltut^ A Bad ? BD-PCD AD C,ita ? ABadoABC.

aa---bb-^cy--- aa 1 ax.


jEqualla igitur funt «?BD cuADCamp;cziABC.

bb-\-cy OD etx. Quod erat oftendendum.


Idem qiioque aliter a nobis demonftratum rcp^ritur Propquot;*^ 20“^ fecundae partis prioris traftatusExercitationum noftrarutnnbsp;Mathematicarum ; ac prstcrea etiam adhuc aliter ab aliis.


-ocr page 401-

3 73

Demonstrationibvs.

Alï^f race dent isTheoremattsAnalyJis,ftifpnendo tantum 2.6 ^ 47 Tropfitiones j^rimi libri Euclidis.

Demiffis ex D fuper AB, BC, perpendicularibus D F,nbsp;D G,patet,ob anguIumA B Cnbsp;reéla B D bifariam divifum,nbsp;ipfas-DFamp;DG, utamp;FBamp;nbsp;B G fefle sequales.nbsp;Deinde efto etiam B E perpendiculars ad A C , fitquenbsp;A E 00 4nbsp;. BDoo^

A D 00 c B C 00 a:

D C 00/

F B vel B G 00 ?,eritque A F 00 a—f, amp; G C 00 x—t.nbsp;amp; E D oO'J'jCritque A E ooc—Vynbsp;amp; E C 00/ V.

^-Seci^ in aliis quoque terminis inveniripoteft, qiiserendoeam per 3 latera trianguUD B C, hoe padto:

-ocr page 402-

374


De c o n c


INNANDIS

fer 47 pimi.

, nbsp;nbsp;nbsp;. , Subtr,

¦ixt tt


del. utrlnque t t,amp;c

tiansf.77amp;KK


qbd

________ ‘W/. nBG

? DG.77—xx zxt—tt 00 il)—/?. ? D G


div. utrlnque pet i x


ztZlCBG GBC gBD —GDC ¦ ^xt OO xx bh—yy *


fit t 00


Siveigiturqu2raturfper3MateraA'‘ ABDffiveper3“latera a'‘D B C, elucet utiqueinde * Propofitio 13 fecundi libri Euclidis, ac prstcrea quomodo haec ipfa adhibenda fu ad FBnbsp;velB Ginveniendam.


Erit itaque


^a bb~cc ^ xx-hbb—yy anbsp;nbsp;nbsp;nbsp;X


divifo utïoque denominatore pet 2,in- _

ftituatutniultipUcatiopercruceni aax^hhv_

transf. quantitates, ut, qua: in i t duftac quot;^X-\-vt)X CCXXaxx dtip gyy


funt ab una parte habeantur nbsp;nbsp;nbsp;bbx-abboOaxx-ayy CCX—aax

div. utnnque per x — a — nbsp;nbsp;nbsp;__

Quseraturjam'yper 3“Iateratrianguli ABD per 47 primi.

Subtr.lt;[ “af’'*'* b. Subtr. ^ nbsp;nbsp;nbsp;° 5!?

iGAE.rf' — zcv vv nbsp;nbsp;nbsp;iiquot;:/.GED

? E B. nbsp;nbsp;nbsp;c 2 c'j'—w 00 bh—z'2'.GE B


del. utrlnque v v,Sc transf. a a Sc cc


div. utrlnque pene


1 cv OD ^b »c—aa ,


tquot;


fit 2/ 00


hh'^c c—'Ua^


Sed V quoquein aliisterminisinveniri poteft, qusrendoeam per 3“ latera trianguli D B C, hocpaöo;


Subtr.


-ocr page 403-

Demonstrationists. s7S

fer 47 primi

? EB. bb*—vv CO XXyylyvw.? EB

“TS:;Ï quot;Ï5CDE ?bc-ddc-obd


Subtr.^ nbsp;nbsp;nbsp;--OBC

zyv CD XX-yy—bb t

_ nbsp;nbsp;nbsp;XXyy—hb

fitz/DO --

%y

div. uiinqueperijr

xy

Qusrendo ita^que v per latera D B C, emanat hinc Prop, nfecundi libri Euclidis, ac praeterea quomodo hsec ipfanbsp;debeat adhiberi ut inveniatur E D.

Quare erit.


bh cc-'aa ^ XX—yy-bb

dfvifo utroque denotninatoreper z, inftituatiu multipiicatioperciucem bby ccy — aayöDcxxcyy—ebb

mnsf. quantitates, ut.qusintt i i . i i

duftaefunt, ab una parte habeantui b by-\-C h bZOC X X-^/i ayCyy ccy div. utriiique setnbsp;nbsp;nbsp;nbsp;g: fit b /-JQnbsp;nbsp;nbsp;nbsp;quot;

y-¥e

Dupliciter igiturinvento^^, liabebituraequatio

. nbsp;nbsp;nbsp;• axx-ayy-\-ccx-aax . cxxA-aaycyy—ccy

inter-—V-ir; nbsp;nbsp;nbsp;•

mult, per crucem_^_____,

ax xyay^ -^eexyaa.xy acxxa cyy c^x —aacx

GO.

ex^ aaxyc xyy —eexyacxxa^y acyy accy tranfpofitis tranfponendis, fit_

zacxx cxyy xcx^aac x -^-z eexy 00

2 a a Xy •¥ ^y^ nbsp;nbsp;nbsp;^ c-y—axxy — lt;«’j 2 a cyy

div. utrinque per 2 nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp;—xx—aa z cy.

AD DC AB EG eritque tr a? 00 lt;*7- Hoc eft,erit ut c adj.ita a ad .v.nbsp;. 1nbsp;nbsp;nbsp;nbsp;^„nbsp;nbsp;nbsp;nbsp;Quastertia eftPropolltioli-

arpromdejrco^ - Oif- Jïift„iEucliamp;.

Hiue

-ocr page 404-

37Ó' De concinnandis Hincexiftente^^CO -nbsp;nbsp;nbsp;nbsp;f ^ fiitj locum aj

fubflituatur CAT amp; vice versa: liabebitur^^oo

0 nbsp;nbsp;nbsp;x^anbsp;nbsp;nbsp;nbsp;'

?AD C DDB oABC

ideft,^^30lt;«A:—rj;reu,quodcodemrecidit, nbsp;nbsp;nbsp;33 ax.

Omninoutin ancecedentiTheoremate. Vndctacileelt, cogai-tis B C, AD,amp; D CjinveuireBD.

Qtxód fi aucem, exiftente b b ZO a x cy. pro x fcribatur

^QtbbzD nbsp;nbsp;nbsp;cyvc\bbc ZO lt;*lt;*ƒccy. ideft, dividendo

utrinqueperlt;ï(« — ^^refolvendo aqiia-

? AB—DAD DBD AD DC litateminproportionem,entut^ï^ — cc ad^^, ita cadj. Similiter,fi pro j fcribatur ^ , cmbbzoax—nbsp;nbsp;nbsp;nbsp;vd bbazaaax—ccxx

ideft, dividendo utrinque per —fc, erit nbsp;nbsp;nbsp;33 x. Vel,

?AB—DAD

rcfolvendo squalitatcm in proportionem , crit ut 4^'—cc ad ?BD AB BC

bbt'm. a ad x. Q.u^ quideminfuper oftendunt, quopaöocx tribus lateribus A‘‘ A B D inveniri pollint B C amp; D C.'

Atqtie ita confiat ,Ji adpracedentis Theorematis in-’vejiigationem duntaxat adhibeantur t6ïê ^jTropq/i-ttones primi libri Euclidis, qudratione ex calcttlonon modbidemTheorema^manetyverümetiamEropojïtio iznbsp;amp; fecmdi libri-, i^’‘*féxti,ali£quepropojïtiones dn Eu-• elide non extant es,qna triangulum concermmt,cnjm an-gulm bifariam ejl divifus.

Cat er urn calculum hunc multo prolixiorem ejfe calculo antecedentis Theorematis nemini (tit opinor) mirum vi-deri debet, cum ad illud indagandim fuppofuerimmnbsp;^heorema.qnodei immediatepraceditdumetiamErop.nbsp;T z aut 15 fèmndi: fiquidem rationes, qua in iis compro-bandvs cunCla acJïngiila funtperpendenda, ïllisficjamnbsp;prafappofitü omninopratermittuntur i qua alioquin, fi

rem

-ocr page 405-

Demoj^strationibvs. 3 77 rem i^fampenitiüs injpicere atqite aprimis velutp'ïn-ctpiii, {quemadmodum in Algebraprafertimfieri Jolet,)nbsp;deducere.velimia,longdfier ie for entJpeEtanda. fpua qui-dem hïc refer o, ut quilibet intelligat, nonnullosreperiri,nbsp;et tam in Mathematicü hattd leviter verfatos , quivi-dentes hujufinodi calculum fapenumero valdeprolixtmnbsp;evadere fplurimifue termini» confiantem, demonfiratio-nes Geometrie as ei longè praferunt, non animadvert en-tes ejufdem beneficio elici Theoremata, quibm ad id con~nbsp;catenatim utuntur. Exifiimantes praterea Algebramnbsp;vel hoe nomine nonmagni faciendam ejfe, qubd folummo-do circa aquationes verfetur ac eafdem continue refipi-ciat, quod'fanè ego maximi momentijudicaverim i quip-pe harum ope infinita genera ‘Problematum pro unogenere Troblematum haberi queunt.,ac demum quiequid innbsp;univerfa Mathefiarduiimfeu difficile occurrit, id omnenbsp;per tequationem abfque ulla ambage^verboruminvo-lacrisquamjimplicijfimepotefl explicari.

Problem A.

Datis pofitione duabus reftis lineis parallelis AB, CD, amp;iniis duobus punftis Aamp;E: è punfto F extranbsp;ipfas dato reflam lineam ducere F B D, qu£e a pofitionenbsp;datis abfcindat reftas A B , E D, datam inter fe ratio-nem habentes A F ad C G, feu a ad d.

Series Refblutionis.

Ponatur fadum, quod qus-ritur, hoe eft, fit A B ad E D, ut 4 ad , fitque A F conbsp;CF co ^nbsp;CEcocnbsp;amp; A B CO AT.

Hinc

-ocr page 406-

378 nbsp;nbsp;nbsp;De CONCiNNANbiS

Hincüt A F ad C G, ita AB ad4'=‘”feu ED

a- d -- X / nbsp;nbsp;nbsp;—

a

Sedexfimilitudine AFB amp; CFD eftquoqiie

ut AF ad AB, itaCF nbsp;nbsp;nbsp;ƒ

4 - X- ^/adCD.c -/

Quare erit f» 16 fati oAF,CD CHAB, CF ac-^dx GO bx.

Transfcratur^i/Aradalterampartem , ut incognita? quantitates ab una parte habcantur

critqueacj^) bxdx.

Dividatur jam utraque pars per b—d

amp;fit.y 00 nbsp;nbsp;nbsp;Hoceft, refoluta jequalitate in propof-'

tionein, crit ut^ — dsiAc, ita a ad at.

ld quodarguit, adProblcmahocfolvendum, ftatuendum eflè ut GF ad C E, ita A F ad A B. Vtautemipfum componaturgt;nbsp;repetantur Refolutionis veftigia amp; ab ejus fine per eadem redea-tur ad id unde initium cepit. Quemadmodum fuperius jamfas-piüs monfïratumfuit, atqueetiam hicvidere eft, próEmittendonbsp;prius Conftrudtionem ,, quse fic fe habet.

ConftruBio.

Dufta G H parallels A B vel C D ac sequali C E, agatur ex F per H retfla F H D, fecans A B, C D in Bnbsp;amp; D: dico ABadEDe/Ièjficuc AFadCG,feu-2adlt;£

Finis CompoJltiojm.

AF CG AB ED.

Vnde i6fexti erit, ut ad d, ita x ad ƒ.

coAFjED coCGjAB erit fimiliter af GO d x.

cz]AF,CE

Flinc dempto utrinque communie r.

-ocr page 407-

Demonstrationibvs, 379 cnAFjCE-fCZiAFjED ci]AF,CE oCG,AB.nbsp;. (^uareeritetiam lt;7 af CO a cnbsp;nbsp;nbsp;nbsp;dx.

oCFjAB oAF,CE aCG,^B.

lij

S' *

Erat autem amp;c b x ZO a c d x.

' aCF,AB aAF,CD,fcu,c:AF,CE aAF,ED.

etkbX zo a c af.

AF AB CF CD

critque ex fimilitudine AFB,amp; CFD^t a ad a;,ita b adc / Efto jam E D GO ƒ,nbsp;i=iCF,AB i=iAF,CE oCG,AB.

critque bx ZO ^c-\-dx.

co C G, A B Addatur utrinque d x,

aGF,ABfeut=iCF,AB—aCGjAB c=iAF,CE.

crit Pquot; b Xd x nbsp;nbsp;nbsp;ZO a c

id eft, reduda proportione ad tequalitatem,

GF GHvelCE AF AB Ex conftrudioneeftj ut ^ — d ad , ita a ad at;

Principium Compojitionis.

Relidis igttur hifce veftigiis demonftratio eifdem fuperftru-da crit talis.

Tgt;emonjlratto.

lil

Qiioniam itaquc ex conftrudione GF eft ad G H vel C E , ficut A F ad A B : erit “ redangulum fub extremis G F , A B a pfr iSnbsp;aqualeredangulofubmediisAF, CE. Quibuslladdaturnbsp;mune redangulum fuftC G, AB, crit ^ redangulum fub totab^fri/e-C F amp; A B squale duobus redangulisfub A F, C E amp; fub C G,

A B, Porró, quoqiam ex fimilitudine triangulorum AF Bamp;

CFD, AF eftad AB, ficut CF ad CD; eritquot; redangulumc *fub mediis C F, A B aequale redangulo fub extremis, A F, Cnbsp;hoe eft, ‘‘ sequaleduobus redangulis fub AF, CE amp;fub AF,d/gt;fri/f-E D. Erat autem quoque redangulum fub C F, A B squalc duo-

Bbb I nbsp;nbsp;nbsp;bus

-ocr page 408-

epen 6 fexti.

380 De cokciïJkahdis busredangulisfub AF, C E amp; fub C G, A B. iEqualiaigiturnbsp;erunt bina reélangula fub A F , C E amp; fub A F,E D binis rettan-gulis fub AF, C E amp; fub C G, AB. A quibus fi commune au-feratur redtangulum fub A F, CE, ericetiam rcliquum reélan-gulum fub AF, E D aequalè reliquo redangulo fub C G, A B.nbsp;Vude ' ut A FadCGjitaAB adED. Quoderat faciendum.

Harems qua fracejferunt ‘Problemata ^Theore-mata ïjtim natura cenjéri pojfunt, quorum difficult as m demonjlratmiibus ex calculi vejiigiis eltciendis potiüsnbsp;quam in iifdem fer Algebram folvendis ^ oflendendisnbsp;confijlere judicari debet. Etenim cum in Algebra Ero^nbsp;blemate aut Theoremate ad z_yEquationem^erduöfo hacnbsp;fecundüm certasregulas reducatur refolvaturque,at w-rb demonJiratioGeometrica,qua ex eorum calculo depro-menda ejl , non femper eifdem legibm Jlt obnoxia, fed di-*nbsp;nbsp;nbsp;nbsp;verjimodèproutrequiritur, immutanda veniat, ut ipjd

commode [elicit er que per Geometria Element a explice-tur: vijum nobis fuit hic confequenter illirn contrarium in addubfis aliquot exemplispatefacere, utpote in quibusnbsp;pracipua difficult as in tpforum per Algebram enodatio-nefit a ejfe apparent. In quem finem duos primüm ^la-fiiones Arithmetic as in medium offer am, ut, ipfis beneficie calculi hujus Geometria folutis, cuique fiat manife-ftum, quopaPio illius ignari deinde ad eafdem fohendasnbsp;ratiocinaripofiint, vulgaribu^ tantum Arithmetices re-gulis infiruili. ^ibus aliquot ^afiiones Geometrie as e-jufdem generis fkbjunBurus fum, quofimul conjletpluri-mas etiam tales reperiri, pofl quorumfolutionem Alge-brdicam ultrb velut fefe offert fohtiotpfarumGeome-trica, ita, ut quod illius demonfirationem infuper concer-nit Geometria Element a jam edoEios non effugiat.

Q_V^STI0. nbsp;nbsp;nbsp;•

partis lihri OEnopola duplex habet vinum, unius 8 (iufris, alte-eScIu. nbsp;nbsp;nbsp;conjiat cantharus. Vult autem mixtionem

face-

-ocr page 409-

il


D E M o N S T R A T I o N I B V S. 381

facere,itautdoliumvinivendere^offlt 35 florenis. ^£- tiontmiu-ritur, quot cantharos utriufque ad hanc mixtionem ciendamftmere debeat ? •nbsp;nbsp;nbsp;nbsp;tnatict-

Ponatur eumdebere fumere a; cantharos primi 8 ftufr.

Scy cantharos fecundi i4ftufr.feu b.

Deinde fupponendodolium continere 80 cantharos feu c, amp; pretium 35 flor. vel 700 ftufrorum, quoipfum vendi debet,nbsp;vocari d; erit x 7 oo cnbsp;Sc xOD cy.

Quatratur jam quanti conftent canthari utriufque vini, quo dolium impleri debet: dicendo

Cmth.con/tat quanti confiabunt Canth. ftufr.

I —- a - X / facits x. conflant

canthari primi vini, in doliumnbsp;infundendi

Ca.nt\i.confiat ftufr., qmnticonfiabunt Canth. ftufr.

I ' b --- y / facit by. conftant

• nbsp;nbsp;nbsp;canthari fecundi

vini, in dolium infundendi

-— ftufr.

eritque fumma ax-^-byzod.

ax ZOdby

tiansf.ij'inalt.pait. lt;

d—iy

divid. uttlnqaepei«

fit* 30

Erat autem ScxZDcy. Quarc erit c —y ZD

iRult.uttinquepero ¦


ttinif.quantitates.ut qua: duUz funt unam te- -


AC—ay 30 d—by


neantzquationispaitera _ay ZD d

div. uuinquepei i— » •——


¦ae


o r nbsp;nbsp;nbsp;d—ac , I d

Sc hty zo yyy: vel


• \ac


i--ld eft, erit ut

» nbsp;nbsp;nbsp;h — a

«adi, kidaczdy.

B b b 3 nbsp;nbsp;nbsp;Qua.-


-ocr page 410-

De concinna nd i s

Qua:ftione hac ita refoluta, ut conftet, quopado inqusfiti invencionem circa haecfaciendaratiocinari liceat, infpiciaturfe-quens illorum interpretatio.

Mak. c, 8o Canth. feujdolium Subtr. per a. 8 ftufr. .nbsp;nbsp;nbsp;nbsp;Ex d. 700 ftufr. conftat dolium plenum

-- nbsp;nbsp;nbsp;vino 8 amp; iqftufrorura

fiunt ^ c. ö’qo ftufr........nc. 6^0 ftufr.

num vino 8 ftufro^ rum.

conftat dolium ple- Relinq.öï—ac. (^oftufri, quibus dolium plus

ftufr.

Ex b. 14

fubtr.lt;«. 8 Canth. b—lt;«.6^ ftufr.'—I—

^ifterentiapre-tii unius can-thari

conftat impletum vino 8 ftufr. amp; 14 ftufrorum,quam plenum folonbsp;vino 8 ftufrorum: vel etiam, quibus can thari iqftufrorumin do-lio contenti cariores funt cantha-ris 8 ftufrorum , illorum loconbsp;fumptis.

fubtr.

c. 80 Cantb.dolii

dac. 60 ftufr./facit feu 10 canth. 14 ftu-

—a

differentia pre-tiicantharorum in dolio

_frorum 007

rel. cj.jo canth. 8 ftufrorum CD .V.

V S T I O.

Ancilla forum petit, habens 91 flufros, utiis poma flnhlibri^ pira emat ; ubi venietis , 10 poma ipfi ofïèrunturnbsp;primi j ftufr. amp; X 5- pira z flufris. Quaeritur, fi utriufque fruétusnbsp;fiomT' fimulioo habere vclit, quotpoma amp;pirafèorfim acci-nojirarum perc dcbeat ?

Mathc’

matica- Ponatur ancillam debere accipere x poma, undecumutriuf-nmi. quefruóèus loofeuiïfimulpropiftufr. feu ^habere velit,fcqui-tur ipfara reciperc debere et —^ ar pira.

Hinc cum 10 poma feu cofferantur i ftufro feu ^, amp; 2 5 pira feu e rtufris 2 feu ƒ, quaratur quantijam conftcntaflumpta.vnbsp;poma, amp; A—A'pira.

Di-

-ocr page 411-

Demons trationib VS. 383

Dicendo:

Vom^confiant^iüïn.ytjHanticonfiabuntVoim nbsp;nbsp;nbsp;'

c---d -------—A-/facit y.conftantpomafumcnda

Pira conftant ftufr., quanticotiftabuntVlts.

e --—ƒ ———-— a—X l Ï3ic\x./——conftant pira fu-

menda

nbsp;nbsp;nbsp;7-nbsp;nbsp;nbsp;nbsp;iiur

. r nbsp;nbsp;nbsp;dex cfacfx

entquelutnma--— zo b.

muit. utrinque per c e tzansf. e/4 ad alt.partemnbsp;div. utrinque pet de — cf

ftufr.

d e x cfa—cf xZOc b e d e X'—cf xzocb e—cf A

amp; fit .VOD

t/f — cf

Ad fraffionishujus refolutionem, fiat ut aid, ita e ad quar-

• nbsp;nbsp;nbsp;Inbsp;nbsp;nbsp;nbsp;1

tam, qu£e vocetur^: cntquer ^ X) «Yndepro a X - ^.......

fcribi poterit ax nbsp;nbsp;nbsp;velnbsp;nbsp;nbsp;nbsp;• Deinde fiat ut e ad/, ita

^ , nbsp;nbsp;nbsp;he—fa

A ad 4'“quot;’, qu* vocetur h: eritque e h zo fa; ita ut pro a X -jzZTf

fcribipofllt a X nbsp;nbsp;nbsp;. Hinc fi demum fiat, ut^—/ad^, ita

y — /^ad 4quot;quot;', criteaXA, quantitatiqucefitasfumendorumpo-morum.

Qua: itaque ad quasftionis folutionem citra Al^ebram fequca-ti modo argumentandum efle inferunt Poma ftufr. Poma

ede nbsp;nbsp;nbsp;g

jo-I-25 / facit 2-j ftufr. conftant 2 5 Poma.

fubtr.f 2 ftufr.pretium 25 pirorum.

Relinq.^—ƒ. i ftufr. quo 2 5 poma cariora funt 2 5 piris. Pira ftufr. Pira Subtr.

e nbsp;nbsp;nbsp;fnbsp;nbsp;nbsp;nbsp;Anbsp;nbsp;nbsp;nbsp;/i.jj iftufr. conftant 100 poma amp; pira fimul

2 j-2——100/facit/).8 ftufr. conftant 100 pira

relinq. ^ — h. 1 -^ ftufri, quibus 100 pcMia amp; pirafimulcariora funt 100piris, veletiam,

qui-

-ocr page 412-

384 De concinnamdis

qiiibuspomaincentenarto contenta cario-rafuntpiris eorumlocofumptis. ftufr. differ. Poma ftiifr. differ. Subtr.

—f nbsp;nbsp;nbsp;enbsp;nbsp;nbsp;nbsp;b—hnbsp;nbsp;nbsp;nbsp;agt;ioo

\-— 2 5 ——— i~l facit AT. 7^ poma

Sc a — Ar. 2 5pira.

Problem A.

Metiri altitudinem turrisAB, utamp;diftantiam AC, beneficio duorum baculorum C D, E F, daris G D 20 ^,nbsp;CEx^,amp;HFcor.


Efto A C GO AT ,

amp; AB GO/.

Series Analyfeos.

’ABF

Adeo-

Dufla IF parallela A E, erit propter fimilitudinem amp;GDF

ut A Bad IF vel A E , itaGD ad KF vel C E.

ƒ nbsp;nbsp;nbsp; x b.........lt;* / b,

BDG amp;BFH

Ac proinde per 16 fexti byZDax-^ab. ,

Eodemmodo, erit propter fimilitudinem A utBDadBF, five IK ad IFnbsp;^nbsp;nbsp;nbsp;nbsp;hoccft, ACadAEjitaGDadHF.

X-A? ^-a! c.

-ocr page 413-

Demonstrationibvs. 385'

Adeoque per 16 fexti

c a: CD

Auferatur utrinque^Ar,

ScHtTAT'—axZD^b’

Dividamr jam utraque pars perr—a,

eritqueA;0O...... Hoceft, refolvendo sequalita-

teminproportionem, eritut c — lt;«ad 4,ita^adA;.

lam cum eiderh aequalia inter fc quoque fint aequalia cïh igt;jr CD cx. Hoceft, erit ut J’adc, itaArad^.nbsp;Quodfiautem invenireliibeat^, non inventa priüsa', fubro-geturinhujus locum in aequatione ultimo hïc inventa valor ejiisnbsp;a b

inventus-,

ca

f' nbsp;nbsp;nbsp;jnbsp;nbsp;nbsp;nbsp;ü-b C

faetque hy CD ^ •

Vbi, fiutrinquedividaturpcr^, invenieturjCD —Quaj

quidem xqualitas in proportionem fic refolvitur, dicendo: ut c—lt;i ad lt;ï, ita c ady. E quibus itaque hujufmodi Conftruélio feunbsp;operand! modus elucefcit.

Sumpt^ H L cequali G D, junftaque D K , fiat ut caaaa, hoe efl, ut F L ad L H, five F D ad D B, fivenbsp;etiam F G ad G A, ita E C leu ^ ad C A feuAr; amp; ita quoque F Fi feu r ad A B feujy.

Cujus demonftratio cx 2“^“ amp; 4“ fexti libri Elementorum per-fpicua eft, quippe conGderando reélamDL ipfi B H parallelam fecare proportionaliter reeftas B F, F H, perinde ac D C, qux ipfinbsp;ABeftparallela, fecatredas A F, AE; ut amp;rfcöamF E eidemnbsp;A B parallelam,facientem A’“ fimilia G F H amp; G A B.

CjEterum ut praxis hujus Problenèatis cuivis obviafit, viftim fuitilludper numerosilluftrare, ut fequitur.

digit.

EftoGDx^30-4 C ECD^OD 30nbsp;amp; HF 00 fX 25

Fm //• nbsp;nbsp;nbsp;Cccnbsp;nbsp;nbsp;nbsp;Vt

-ocr page 414-

385 De concinnandis

VtF LadLH feu F D ad DB,

fivecdamFGadGA, _ nbsp;nbsp;nbsp;£(..30, .jCA.jfo.

1 H» it^FH.2 5 A B.doo,

P R O B L E M A.

Metiri diftantiam turrium A, B, cüm ad A pcrve-nire licet, datis C A co a,A D co C D x A E x amp; C F X e.

Efto A B X AT.

Series Analyfeos^

Dudia G E parallela C D, fiat propter fimilitudinem A™quot;* ADCnbsp;amp; A E G,

ut A D ad D C,itaA E ad E G

^- c--dl

itemque

ut A D ad A C,ita A E ad AG.

dl

a

T

Hinc propter fimilia A‘“CBFamp;GBEnbsp;crit ut

CFadCBjitaGE add.A B.x

e—(t x—-^/adGB. —-—

Ac proindc per 16 fexti erit O C F,G B aequale cn C B,G E

ade hex acd cdx bnbsp;nbsp;nbsp;nbsp;b '

V

H\

Inventa igitlir jequatione , ut evanefcant fradtiones, multiplice-tur utrinque per amp; fit lt;}fl!e nbsp;hex'Xgt;acd cdx.

Transferantur jam quantitates,

’ nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;ita

I

-ocr page 415-

Demonstration iBVS. 3^7

ka utqus in ar duösefuntunam partem squationis obtmeant,re-* liqus autem alccram

fietque^(?x — cdxZD tieda de.

acd—ade


Denique dividatur utrinque per becd

eritqiicxoo-

lam ut asqualitas h^c omnium facillimèin proportionem rc-folvatur, fimulque inde eluceat, quo pacio quis ratiocinari tenea-tur, utquaeiïcamlmeamABleu x ex datis quam breviiïïmè in-veniat : animadverterc oportet , qiisnam litera plurimum omnium in hifce terminis reperiatur. Quas igitur cum hïc de-prehendatur eflè d, ipfaque fe ter prodat, ubi reliquje non nib bisnbsp;oiFcnduntur, faciendum eft, addeprimendas dimenliones, utillanbsp;in omnibus terminis inveniatur. In quem finemiifiacutc/ad^,

ita ad 4”quot;', quae voceturƒ: erit dfzob ^,ac proinde x CD

feu nbsp;nbsp;nbsp;. nimirum, abbreviando terminos omnes per d. Vbi

fi demumbat ut ƒ—cad^'—e, ita^adq”'quot; ; erit ipfa CD at, hoe eftj CD quaefitse linea; AB. Atqueitaapparct longicudinem ejusnbsp;duabus regulis triumfeuproportionuminveniri poll'e, quae aliasnbsp;^'’“autpluribusinvelligaiidaforet, fi nullum inrefolvenda hacnbsp;fradiionc fierct difcrimen.

ide

, nbsp;nbsp;nbsp;, etiam alio mo-

b e c a

doinduas proportionum regulas eflTe refolubilem , qujefingute ficutpratcedentesnon prtEterunamdimenfionemagnofcunt fivenbsp;omnino fimplices exiftunt. Nimirum confiderando in ^uobusnbsp;terminis reperiri cdjamp;cin fingulis rcliquorum duorum reperiri e;nbsp;adeout, li planum cd inaliud tranfmutetur, cujus unum latusnbsp;fit e, litera e (icin omnibus terminis haberi valeat, qu* deindenbsp;omitti poffit. Ac proinde li ftatuatur, ut e ad c, ita^/adq”quot;’,

qusevocetur^; erite^x cd, ka ut pro nbsp;nbsp;nbsp;fcribipoffit

Vbi notandum,candem fraSionem

Vndefirurfus fiat ut b-

-d, ita

i, e—eg _ h—g

(«ad4“”: erkeaxx, linesqusefitatAB. Qusequidem animad-verfio, cumin abftradio fiat nuliafadla calculi relatione live re-Itridtione adfigurs lineas, luculenteroft^ndit, quamperperam judkent illi, qui non rite perfpicientes hujus Geometrie Metho-

C c c 2, nbsp;nbsp;nbsp;diini

-ocr page 416-

¦7


388 nbsp;nbsp;nbsp;De concinnandis

dum conftruöiones concinnas aliunde potiusquam exejuscal-culo derivari autumant. Quod utique plurimis exemplis demon-ftrare poflem, iisque non inelegantibus, fed cum id prolixins explicare non (it hujus loci,h*c in medium attulifle fufFecerit.

Dcnique ut pateat, quo padto prscedentis fradionis refolutio adfigurse lineaspertineat eaquefimul nobis manifeftet, qualesnbsp;linex ducenda: fint, qux nos ad quxfiti finem perducant: confe-quens fuericutea quxad facilitacem redudlionis circa calculuinnbsp;feorfim fumus meditati adfigurxlineas referamus. Conftrudionbsp;igitur five operandi modus tabs eft.

Fiat ut d 2iA b, hoc eft, ut A E ad A D five C H ad CI, ita C F feu ^ ad C K feuf. 1 einde fiat ut ƒ— f adnbsp;ce, hoc eft, ut K D ad D F five ID ad D B, ita C Anbsp;feu ad A B feu x.

Cujus demonttratio ex ipfaproportionalium appHcatione ma-nifeftaeft.


Eadcm manente fradionis refolutione poffiint didse propor-. tionalesdiverfisaliismodisfiguraeaccommodari, indeque velutnbsp;alix conftrudiones concinnari, quibus licet figurx valde dififimirnbsp;les appareant, operatio tarnen una cademque exiftit. Quasqui-dem omneslnc exponerc propter earum multitudinem fuperva-cuum duximus. Idem intellige cum prxcedens fradio fecundonbsp;modo refolvitur.

Vndecolligerelicet, cum ex fola applicatione liarum propor-tionali^m, manente refolutione fradionis aiueademaliquantu-lumimmutata, complures vixuUroquafifefeprodant, quibus a datis ad quxfitum perducamur, quanto ideocum emolumentonbsp;hujus Geometrix calculus ad omnifarias quxftionesadhibeatur;nbsp;utpote cujus beneficio non modo difficultas omnis breviter obnbsp;oculos ponitur, fed etiam quid circa illas fit fadu opus plene edo-cetur.

Cxterum ut iis, quibus hujus generis Problemata arrident» qux abfque ullo inftrumento Mathematico in campo perficinbsp;queunt, etiam praxis allatiProblematisconftet, vifumfuit illudnbsp;ervando priorem fradionis refolutionem fecundum fuperioremnbsp;cjus applicationem per numeros illuftrare, ut fequitur.

Efto

-ocr page 417-

Demonstrationibvs. 389 pcdum

Efto C A 00 GO 4')0 ADoO^GO 390nbsp;^nbsp;nbsp;nbsp;nbsp;CD0OCX420

AEooofOOiiS amp; CFgo eGO 2.52-

Turn fi«t Vt A E ad A D,nbsp;five C H ad CI, ita C F ad C K

225 —_

CD.420

fubtr.C D.420 fubtr. CF.252 nbsp;nbsp;nbsp;ped.

Deinde,utDK. nbsp;nbsp;nbsp;ad FD.i68,itaCA.45o/adAB.45oo.

Sive ut I D ad DB

P R O B L E M A.

TrianguU ABC produfto latere AC ad D, duft^-* que rcAa D E F , fecante C B, A B in E amp; F, dantur ABgoö, BCgo^, ACoo^-, CDGOlt;/,amp;CEao£’:nbsp;oporteatque invenire A F go at.



Series Anal^feos.

Duöa FG parallela B C, fiat propter fimilitudinemtriangu-lorumABCamp;AFG

ut A B ad B C, ita A F ad F G

; nbsp;nbsp;nbsp;I hx

a nbsp;nbsp;nbsp;bnbsp;nbsp;nbsp;nbsp;X f — .

Itenv*

Ccc 3

-ocr page 418-

55)0 nbsp;nbsp;nbsp;De concinnamdis

Itcmque

utABadAC,itaAFadAG nbsp;nbsp;nbsp;ACnbsp;nbsp;nbsp;nbsp;GC

a--c-X ! ^.quxfubduétaexc,

Hinc propter fimilia nbsp;nbsp;nbsp;C E D amp; G F D

add. CD.d

- erit

utE Cad C D, ita F G

-d--^’^/adGD. -

a

Ac proinde per \6 fexti

£nEC^,GD coCD.FG

d^ecaeey. dbx -----X--.

mult.utrirquepeta

/

add.utriaqucc div. utiinque per d 6 c


öi a e c a e—c e xZüd b x dae cadbx-^ cex


d ae-^cai

db-\-c e


amp; fit


• OOa;.


Ad rerolvendam hanc fcadionem, fiat ut e ad ita ^ ad 4quot;^™, *

qU£E vocetur/;critquc/eXlt;^^jadcoqueA*00 nbsp;nbsp;nbsp;feu'^^^.

Deinde fiat ut f ead^, italt;s(4-ead.v. Quod iplum docct, ut ex datislineis inveftigetur quxfitalinea AE , ducendam.cflccxBnbsp;lineam BH ipiiFED parallelam , donee occurrat produdaenbsp;ACDinH. Cumcnimftatucndumfitutead/5/,hoccft, utCEnbsp;ad C D , ita ^ feu C B ad : patet hanc fore ipfiim C H. Acnbsp;proinde fi porrb fiat ut ƒ 4- e ad n, hoe eft , ut A H ad A B, itanbsp;d c feu A D ad x : manifeftum eft inveniri hinc quantitatemnbsp;quïfitx linesE A F; ita uthïc fieucin duobus prsceeientibus Pro-blcrnatis demonftratio exfola proportionaluimapplicatione pernbsp;fcperfpicua fit.

Quódfiainem quisalio opcrandi modo aut etiam eodem fed aliarunvIincarumduduqujEfitam lineam A F invenire dcfideret,nbsp;obfervarc potcritea, quteanobisin antecedenti Problemate in-dicatafiint. . »

Catteriitn cum amp; praxishujus Proble.matis inextruendis for-talitiis, choniatibus ,promontoriis, aiiifve, nonparvi ufusexi-ftat; niinirum, ubi in fluvio, mari, aut locis paludofis a cecto

pundo

-ocr page 419-

D emonstrationibvs. 391

pundo ceu termino reétalinea .dcterminari debet, datum comi-nens virgarum pcdumve numerum; non abs re fuerit, fi amp; illius praxin paucis hïc explicavero, prxfertim cum abft|ue ullo inftru-niento Mathematico negotium hoe expedite licctit.

Ponamus itaque in direciuni ipfius AC a C ufque adDdefi-nienda efle reöa C D, dftntinens i o perticas feu virgas. In quera finem eredtis tribus baculis, A, C, amp; B, efformantibus triangu-lumqualecunque AB C, ac inter Bamp; C ercöoubicunque quarto E,fi menfurentur ABjBCjA C, amp; CE,fitque,ex.gr., AB COnbsp;4COl5,BCcO^OOl3,ACODeQO i4,amp; C E CO e Xgt; 5perti-carum feu virgarum toportebit ex hisjuxta amp; ipsa C DcOfS^OOionbsp;quxrere longitudinem linese AF, perinde utfupra atqueexfc-quenti operatione videre eft.

CE nbsp;nbsp;nbsp;CD CBnbsp;nbsp;nbsp;nbsp;Add.

5-10——i3/adCH.26’ nbsp;nbsp;nbsp;,AC.i4

add. AC. 14 AB CD. 10

AH.40-15--AD.24/ad AF. 9.

Hinc fiab A versus B in redta A B menfurentur 5? pertica: feu virga:, atque in F hujus menfurationis termino bacillus erigatur,nbsp;fiet, ut, fi a C in diredtum ipfius A C progrediamur, extruendonbsp;aggerem aut etiam navigando cum fcapha , donee perventumnbsp;fuerit in diredtum ipfius F E, redla C D tune 10 perticarum feunbsp;virgarum fit futura. qualis requirebatur.

Qui plura hujus generis Problemata videre defideret, adeat Appendiceinnoftramde Simplicium Problematum conftrudiio-ne, quamuna cumExercitationibus noftris Mathematicishaudnbsp;itaprideminlucememifimus, ubiiftafufiüs pertractantur^ etiamnbsp;fincullius calculi adjumento.

P R O B L E M A,

cujusfolutione innotefcit ,qud rationeprior a duoTheore-mata 11quot;' Capitis i”' libri Almagejii P t o l e m i inventafuerint feu inveniri pojfmt.

Inredfas AB, AGdudisutcunqueredtis BE, DG, fe mutuo deculTantibus in Z, deturratio GDad DZ,

ut

-ocr page 420-

592- De concinnandis

ut aoL^b, nee non ratio Z B ad B E, ut f ad^: oporteat-

que iiivenire rationem G A ad A E.

Series Analyfeos.

Efto GDoDa

D ZGO^,eritque Z Gco^—b B 00 ^

B£ 00 lt;^,eritqueZEoOö?—e AGxa:

amp; A Ex/jeritqueE Goo.*-—/.

Ducla D F paraliela E E, ecit per 2 fextinbsp;ut GZ ad ZD, itaGE Ex AE. ynbsp;a^b-b-x—y! adEF.

rdAF.f^i.

a~ b

Turn fiat propter fimilia A'“ G Z E amp; G D F

utG Z adZE, itaGD ,

.Lj nbsp;nbsp;nbsp;/ adDF.-- .

a—bd—c-a nbsp;nbsp;nbsp;a—b

Quibus fic conftitutis,erit es fimilitudine A'””*quot; D A F amp; B A E ut D F ad AF, ita B E ad A E

ad-ac ay-bx. nbsp;nbsp;nbsp;, ,

Etfitper i6 fexti

adv

-d/ y

‘“^y-

-hdx

a-b nbsp;nbsp;nbsp;a-h

Hoe eft, omifl'o communi denominatore ab eritadyacyxxidy-— b dx.

Vnde dempto utrinque ady, ac reliqui$hinc inde tranflatis, ut figno adficiantur

habebitur hdx 00 acy.

Quï jequalitas in proportionem fic refolvitur utaradj, ita «IC ad^

^ nbsp;nbsp;nbsp;Quod

-ocr page 421-

D emonstrationib-vs. 395

Quod ipfutn docet, rattonem qusefitam G A ad A E feu at ad ƒ eflTecompodtamexratione GDadDZ feu^ad^, amp; exrationcnbsp;Z B ad B E feu c ad ii!, id eft, rationem G A ad A E per 2 3 fextinbsp;elTe eandem, quam redlanguli fub GD, B Z feu 4 c ad reódaugu-lumfubBE, D 'L{cw.blt;i. Atqueita conftat, quopadtoprimum •nbsp;didtorum Tlieorematum inventum fueritfeu inveniri poflïc. ldnbsp;autem ex Rheinoldi verfione ita fotiat.

IndiiasreUtasUneas AB ^ AG dedu[i(e duare^ta gt;¦gt; linea BE ^ GTgt; fee ent fe mutub in pmBoZ. Dico'^nbsp;quod ratio G A ad A E compojita eji ex ratione GD adnbsp;D ex ratione ZBadBE. ^nbsp;nbsp;nbsp;nbsp;»

Hinc poftquam innotuit, quo pafto datis rationibusGD ad DZ,amp;ZBadBE etiam dari intelligatur ratio ipfius GA adnbsp;AE, utpotequx ex datis hifce rationibus eft compofita: baudnbsp;inutile fuerit, fi ulteriüs hk oftendam, quibus datis lineishsecnbsp;qusefita ratio exprimatur, quandoquidem ratio dari dicitur cuinbsp;eandem exhibere valemus.

In quem finemfiinventa ratiO(i£'ad^/a! ad communem altitu-dinem redigatur,quod quidem quadrupliciter fieri poteft, fumen-do ad hoe aliquam ex datislineis,obtinebitur quaefita ratio in fim-plicifllmis terminis.

Etenim aflumendo communern altitudinem e, fi fiat ut cnAd, itanbsp;b ad q”quot;’, qua: vocetur e : eritnbsp;ceöDbd, ita ut quaefita ratio fitnbsp;eadem ,qua:^Jcadc^jhoceft, re-jeSa communi altitudine e, ut ^nbsp;ad e. Quod ipfum Ptolemsi fi-guram prodit, in qua ex pun(fto Enbsp;duóta eft E I parallela ipfi G D.

Si eniin in ea fiat ut e ad , id eft, ut ZB ad BE , ita DZ feu^adnbsp;4quot;™ e, erit ea linea EI j ita ut G Dnbsp;ad El feu a adequaefitamrationemmanifeftet, eandem quippenbsp;quateftipfius GAadAE. Vtpatetex q^fexti, propter fimili-tudinem A™™ D A G amp; IA E.

Sic etiam aflumendo communern altitudinem fifiatutlt;* ad^,

Tars IL nbsp;nbsp;nbsp;D d dnbsp;nbsp;nbsp;nbsp;ho«

-ocr page 422-

De

CONCINNANDIS

hoe eftjUt D G ad D Z, ita H G vel B E feu d ad 4^^™, quae vo-cetur ƒ: eric ea oo Z I. Et fitnbsp;afzobd, ita ut quïfita ratio fitnbsp;eadem, quae^jcad/*/,hoceft,nbsp;rejefta a communi altitudine,nbsp;eadem quse c ad ƒ feu B Z adZ 1.nbsp;Hanc autem eandem eife, quamnbsp;ipfuis G A ad A E, ita patet.

ProduiSis namque A B, G H donee eoëant in K, erit propternbsp;fimilitudinemnbsp;nbsp;nbsp;nbsp;BDZ,

K'

K D G, lineamque D H fimili-terin utroqueduöam, ut BZ adZ I, itaKG ad GH feu BE. VtautemKGadBE , ita eft,nbsp;propter fimilitudinemnbsp;nbsp;nbsp;nbsp;KAG amp; BAEj quoque GA ad

AE. Quareetiam BZadZIerit, ut G A ad A E. Vnde liquet, fi a pro eommuni altitudinefumatur, ducendam efle ex G reöamnbsp;GHipfi BE parallelam, doneeoceurratredz ex B duótx ipfinbsp;A G parallels in H : eritque , junda H D , B Z ad Z I rationbsp;quaefita.

Haud feeus, fi affuma-tin: eoinmunis altitudo fiatque ut ^ ad 4 , hoe eft,nbsp;ut Z D ad D G , ita BZnbsp;feu c ad 4'^^quot;' , qua: voee-tur g: erit ea co I G. Et fitnbsp;bgZD a c,'\x.% ut quatfita ratio G A ad A E eadem fit,nbsp;qu£E bgzA bd, hoe eft, re-jeóta eommuni altitudinenbsp;eadem quae ^ ad lt;3! feu J Gnbsp;ad B E. ut patet ex fimili-tudineA^^IAGamp;BAE.

Quodipfumarguit, fumen-'do b pro communi altitudine, ducendamefteex Gredam GI ipfi BE parallelam, donee occurfatproduda: AB inl, ut ha-beatur ratio quaefita I G adB £.

Nee

-ocr page 423-

D emonstrationibvs. 395'

Nee alitcr fit, fi , affumpta communi altitudine fiat ut dnbsp;adc, hoceft, utB E adB Z, itanbsp;GD vel I C feu a ad 4'=*'quot; , qua»nbsp;vocetur/?: eritea 00 D F. Et fitnbsp;dhzoac, ita ut qujefita ratio fitnbsp;eadem , qus dh Tidl^d, hoe eft,nbsp;rejeóla communi altitudine d^nbsp;eadem qua? ^ ad ^ feu D F ad D Z.

Hanc autem eandem cfl'e , quam G A ad A E, itapatet.

Eft enim, propter fimilitudi-nem BDF amp; BIC, lineamque BE in utroque fimiliter ductam, ut DF ad D Z ita CI feuD GadlE. Vt autem D Gnbsp;ad I E, ita eft, propter fimilitudinem DAGamp;IAE, GAnbsp;ad A E. Quocirca amp; D F ad D Z erit, ut G A ad A E. Atque itanbsp;liquet, fumendofslprocommunialtitudine, ducendamefleexGnbsp;redam GCipfiB A parallelam, donee occurrat redcEper Eipfinbsp;D G parallel» in C, rationem quxGtam efle D F ad D Z.

Caeterüm ut pateat, c[ua ratione demonftratio prxcedentis Theorematis, qualis a Ptolemso affertur,ex allatis deduci poffit;nbsp;ut amp;quopado exindcplures alias demonftrationes fimilescon-ficereliceat: vifumfuiteandemunacumaliistribus, amededu-dis, hic fiibjungcre, calculique veftigia, quibus innituntur,fimulnbsp;bic adhibere atque patefacere.

Vtfupraeft nbsp;nbsp;nbsp;Rati®

ZB BE DZ IE

GA

ad AE

c—'—d--b! e

ac.,

SiceZObd.

vel ac..

feu GD

EI

a ,



.DZ.BE


mcd.tcrm.


ZB


d.


De-

Ddd z

-ocr page 424-

39lt;5 nbsp;nbsp;nbsp;De concinnandis

^emonflratio Ptolem^i.

»gt; ^ucatur enim ^er^unBum E litiea EI lt;£quidijlani , Bine a GE).

, gt; ^oniam igitur Itnea GE)^ EI funt aquidiftantes, „ ratio linea G A ad A E eadem ejt, qua eft line a GE) adnbsp;lineamE 1. ^yldfumatur autem deforis linea Z E). Eritnbsp;5gt; igitur compojita ratio lineaG E) ad line am EI ex ratio-» ne linea GE)adlineamEgt; Z,^ exratione linea E)Zadnbsp;„ lineam EI. ^are ^ ratio linea GA ad lineam AEnbsp;„ compoftta eji ex ratione linea GE) ad lineam E) Z,^ exnbsp;ratione linea E) Z ad lineam EI. Eji autem amp; rationbsp;„linea E)Z ad EI eadem r at ioni linea ZB ad lineamnbsp;„ B E, cum aquidijl antes fint linea EI^ Zquot;D.Ratio igEnbsp;tur linea GA ad lineam A E compofita eji ex ratione li-nea GE) ad lineam E)Znbsp;nbsp;nbsp;nbsp;ex ratione linea ZB ad li-

„neamBE. ^oderatdemonfirandum.

^ nbsp;nbsp;nbsp;Aliter.

Vtfupraeft nbsp;nbsp;nbsp;Ratio

GDDZBEvelHGZI GA ad AE

ub-d l nbsp;nbsp;nbsp;ƒ ac......bd

Xgt;/ nbsp;nbsp;nbsp;\nbsp;nbsp;nbsp;nbsp;amp;LafZDbd.nbsp;nbsp;nbsp;nbsp;velc......af

BZ nbsp;nbsp;nbsp;ZI

feu ...... ƒ

G nbsp;nbsp;nbsp;'nbsp;nbsp;nbsp;nbsp;¦ D7

B,r /¦‘ nbsp;nbsp;nbsp;be *., vclHG ƒ¦

/ nbsp;nbsp;nbsp;mcd. term. • d'

gd

• •

. nbsp;nbsp;nbsp;a.

Dudla GK parallcla ipfi BE, donee occurrat produd* AB inK,agaturBHsEquidiftansAG, occurrens ipfi K G in H, jun-gaturque H D, fccans B E in I.

Quoniam itaque,propter fimilitudinem A'™’ K A G amp; B A E, G AeftadAE, ficut KGadBE velHG^ fed ut KG adGH,nbsp;itaquoqueeft, propterfimilitudinem A^^KD Gamp;BDZ, li-neamque DH inutroque fimiliter duftatn, BZadZI. Quarc

€tiam

-ocr page 425-

D E M o N S T R A T I o N I B V s. 397 cttam erit G A ad A E, ficut B Z ad ZI. Hinc afllimpta forinfecusnbsp;lineaBE, quoniamratio BZadZI compofitaeftexrationeBZnbsp;ad B E , amp; cx ratione B E vel H G ad ZI, id cft ^ propter fimilitu-dinetti A™“HDGamp;IDZ, ex GD adDZ: eritperinderationbsp;G A ad A E compoGta ex ratione B Z ad B E, amp; ex ratione G D

adDZ. Quoderatoftendendutn.

tytdhiic aliter.

. A,

Vtfupraeft nbsp;nbsp;nbsp;Ratio

DZ GD BZ IG GA ad AE

b--a dg nbsp;nbsp;nbsp;•nbsp;nbsp;nbsp;nbsp;ac......bd

D/ nbsp;nbsp;nbsp;\nbsp;nbsp;nbsp;nbsp;SibgZOftc.nbsp;nbsp;nbsp;nbsp;ytXbg......bd

\e nbsp;nbsp;nbsp;quot;ÏG BE

feu^...... d

GD -.BZ/

/ nbsp;nbsp;nbsp;1nbsp;nbsp;nbsp;nbsp;. c med.ter.

¦* DZ

* nbsp;nbsp;nbsp;'-b-

Etenim duda GI parallela B E, ufque dum occurrat produöae A B in I: erit propter fimilitudinem A”™ IA G amp; B A E, iit G Anbsp;ad A E, ita IG ad B E, Hinc cum, aflumpta forinfecus redaB Z,nbsp;ratio ipfius IG ad B E compofita fit ex ratione IG ad B Z, id eft,nbsp;propter fimilitudinem a™” IDGamp;BDZ,exGD adDZ, amp;nbsp;ex ratione BZ ad BE; erit pariter ratio GAadAE cxiifderanbsp;rationibus compofita. Quod erat oftendendum.

Vel et tam hoc^aBo ;

A nbsp;nbsp;nbsp;Vtfupraeftnbsp;nbsp;nbsp;nbsp;Ratio

BE BZ GD DE GA ad AE

dcaj h nbsp;nbsp;nbsp;ac.......bd

dh OD ac. nbsp;nbsp;nbsp;veldh.......bd

1/. { nbsp;nbsp;nbsp;I5pnbsp;nbsp;nbsp;nbsp;DZ.

p/ nbsp;nbsp;nbsp;'x.nbsp;nbsp;nbsp;nbsp;\nbsp;nbsp;nbsp;nbsp;feu/?.......b

' nbsp;nbsp;nbsp;BZ-,

f DG vel IC

.............. nbsp;nbsp;nbsp;'• ’-a.- med.ter,

G nbsp;nbsp;nbsp;'• BE

'd.

Ddd 3 nbsp;nbsp;nbsp;DudS

-ocr page 426-

3^8 nbsp;nbsp;nbsp;De comcinnandis

Diiifla G C ipfi B A parallela, doncc occurrat reda?IE C ip(x D G parallelae in C, juagacur B, fecans D G in F.

Quoniam itacj^ue , propcer limilitudinem nbsp;nbsp;nbsp;D A G amp;

lAE, GA eftadAE, ficut G D vel I C ad I E; at ut I C ad lE, itaquoquccft, propter iïmilitudiiiem A™quot;'B I C amp; B D F,nbsp;lineamque BE in utroque fimiliter dudam, D F ad D Z : eritnbsp;cciam ,G A ad AE , ficut D F ad D Z. Aflumatur jam forin-iecus linea D G. Hinc cum ratio D F ad D Z- fit compofitanbsp;ex ratione D F ad D G vél I C, live B Z ad B E, amp; ex ratio-ne D G ad D G: ent hmiliter ratio G A ad A E compofita exnbsp;ratione BZ ad BE , amp; ex ratione DG ad D Z. Qiiod eratnbsp;oftendendum.

Idem paritcr de nbsp;nbsp;nbsp;P T o L e m ^ i Theored!ate fcUisque fimi-

libiis eft intelligendum.

Vilde confiat,fraJiippofitd Algehrte cogmtionejiatid-quaquam necejfaria ejfe exiflimanda, qii^ de Aationum Logifticacommuniter tradtmtur, nontn ’gis qudmjiddnbsp;cujufvis generis quesjfionesper Alge bram Joh endas mul-t if aria addifiantur Thecremata: ctim^invenireillanbsp;amp; demonjirare ipjius AlgebraJit mnnus, quamquidemnbsp;excolendo non modb ingenium exercetur.féd res ipfafun-ditus er uitur, citra earn verb fapijjime ilia ip fa Theore-maUi nonfatisfelicit er adhibentur.

L E M A.

Latifundii A B C D cognitis omnibus lateribus amp; angulis , ab codem datam portionem refecare , li-neis EF,FG,GH, amp;HE latifundii lateribus'AB,nbsp;B C, C D, amp; D A parallelis, amp; ab iifiicm pari ubique in-tcrvallo diflitis.

lundis AE, BF, CG, amp;DH, demittanturex E, F, amp; G fupcr A B, B C, C D, amp; D A perpendiculares E I, FL,nbsp;F M , G N, G O , amp; E K; at ex D fuper G H amp; H E perpendiculares D P amp; D Q.

Quoniam itaqiie in redangulis triaiigulis AIEamp; AKEqua-

drata,

-ocr page 427-

Demonstrationibvs. 399

g nbsp;nbsp;nbsp;drata, quje fiunt ex AI,

1E nee non ex A K, K E quadrato ex A E per 47nbsp;phmi Elementorum iunt *-qualia , quot;runt amp; ipfa inter fe squalia. Eft autemnbsp;quadratum ex E I sequa-lequadratoex E K, quip-pe ob squalitatem rcóia-rum El, EK, a:qualenbsp;intervallum indicantium;nbsp;Quare etiain qiiadratumnbsp;ex AI quadrato ex A Knbsp;squale erit, adeoque amp;cnbsp;A I aequalis A K. Hincnbsp;cum tria latera triangulinbsp;AIE xqualia fint tribusnbsp;latcribus trianguli AKE,nbsp;erhquoqueangulus I AEnbsp;angulo K A E per 8 priminbsp;Jequalis , ac proinde an-gulus BAD per redïartinbsp;A E bifariam divifus.nbsp;Haud fecus liquet, angu-los ad B , C, amp; D pernbsp;redasBF, CG, amp; D Hnbsp;bifariam divifos elld.

Series Analyfeas.

Efto A B 30 ^

B C 00 ^

CD 30 ^

amp;El,FL,FM,GN,GO^ DP,D Q., velEKoox.nbsp;lam cum propter datos angulos A, B, C, amp; D etiam eorum fe-mifles dati fint, erit in unoquoque triangulorum ad angulos hofcenbsp;conllitutorura data quoque ratio laterum.

Pona-

-ocr page 428-

400 nbsp;nbsp;nbsp;. De concinnandis

Ponatur itaque E I adIAvelEKadK Ae^^c;,utfa(3ƒ EL adLBvel FM ad MB , utead^nbsp;GNadNCvelGOadO C, ut^ad^

amp;: D P ad P H vel D Q ad Q^H, ut e ad i.

Tumfiat nbsp;nbsp;nbsp;EIvelEK AIvelAK

ut e ad/, ita x/ ad

FLvelFM LBvelBM utead^, ita X / ad'^

GNvclGO NCvelCO ut e ad h, ita x / ad

DP velD Q. pHvclHQ, ut e ad / ita x / ad

Additis jam AI, A K, L B, B M,N C, QO,fi ipfarum fiimma auferatur c^a h c d,fumma laterum AB,

B C,C D,amp; D Ajrelinquetiir a lp c d ~~ nbsp;nbsp;nbsp;,

fumma rcdlarum IL, M N, O D , amp; D K, id eft, ipfarum E F, F G, G P, amp; Q,E. Qiiibus fi addatur , fumma ipfarum P H,

-Z X 4- 1 ( X


Fd Q., erit a è c d


fumma late


rum internorum E F, F G, G H, amp; H E. Porrb quoniam portio ablcindenda, quse vocetur protrapezio accipipoteft, cujusnbsp;duo latera fuut parallela, fit ut li A B, B C, C D,amp; D A in rcéiatnnbsp;lineam A R jundlim collocentur, ut amp; E F, F G, G H, amp; H E innbsp;redam lineam ET , trapezium ARTE ipfi portioni abfcin-dends 4,futurum fit sequale. Quocircafi juxta vulgarem tegu-lam hujus area quteratur , addendo fcilicetlatera parallela ARnbsp;amp; E T, St femifl’em fummse multiplicando per ipfius latitudi-nem El feu x, habebitur sequatio inter ax hx cx dx

amp; kjt id eft, aequationeritèordinata, . Cujus radices

erit X xOO

a e x-f- h ex nbsp;nbsp;nbsp;c ex ^ d ex

f K ^—‘ ^ nbsp;nbsp;nbsp; nbsp;nbsp;nbsp;nbsp;¦

mveaiuntur opecando ulterius , quemadmodum pag. 7 hujus

Gco-

-ocr page 429-

DeMONSTRAT'cONIBVS. 40Ï Geometric indicatur, quarum quidem major dumlineam exhibetnbsp;quïlua EI manifeftè majorem, idcirco meritö hïc erit negligcnda.

Quonia n autem ex E, F, G , amp; D intervallis E I vel E K, F L vel F M gt; G N vel G O, amp; D P vel D defcriptis circulis ïeamp;xnbsp;A'Ivel AK, LBvelBM, NCvelCO, amp; PFl vel H Q^tan-genteslqnt complementoriim femiflium datorum angulorum A,nbsp;B, C,amp;D;fictut, fiif pro radio fumatiir, ipfae/, j-, h,8cidi~nbsp;öas tangentes defignent. Qiiod cumeodem modo de omnibusnbsp;aliis figuris rediilineis intelligendum fit, a quibus hujufmodi portie relecari debet: baud difficultcr poterimus, fi angulos A, B, C,nbsp;fimilesque vocemiis externos , at angulum D internum, utamp;nbsp;cos omnes, qui büjitfce^eneris exiftunt, atqucprteterxquatio-nis conftitutionem fpedemus infuper , qiisenam ad illam refol-vendam five ad qutefitam latitudinem ex eaobtinendam fint fa-cienda, regulam inde generalem formare, qus lic fe babet.

Additis figurae lateribus , multiplicetur fumma per radium 100000 , produt^umque dividatur per fum-mam tangentium , angulorum qui femiffium datorumnbsp;funt complementa , cüm videlicet dati anguli omnesnbsp;funt externi , aut per earundem difïèrentiam , quumnbsp;externi acinterni exiftunt, amp; fitprimum inventum.

Deinde multiplicata area portionis abfcindenda: per radium 100000 , dividatur produeftum per pras-dieftam fumnfam vel difïèrentiam tangentium, amp; fitnbsp;fecundum inventum. Quo fubdufto a quadrato femif-fis primi inventi, ft reliqui radix ab eodem femiflè aufe-ratur, relinquetur latitudoquaeftta.

Inventa igiturper Algcbram via, quaProblema propofitum folvendum lit, ipfius veritas ex fequentis calculi applicatione,nbsp;quse ab ea parum eft aliena , manifefta fiet; fi modó ibidemnbsp;confideraverimus,completeparallelogragamo ARSE, produ-ctisque AE, RTdonec coëant in X,reiftamST, duplumfupranbsp;dióliE fummtevel differentise tangentium referre, atque demillïsnbsp;perpendicularibus R V amp; X y reélam S T ad R V, ob fimilitu-dinem triangulorum STR amp; ARX, eam babere rationem,nbsp;quam A R babet ad X Y.

Pars IT, nbsp;nbsp;nbsp;Eecnbsp;nbsp;nbsp;nbsp;An-

-ocr page 430-

40 i Angul.nbsp;A. 50. o'

De concinnandis

Add.

femiffis. 2 j.o'jCjusTang.Compl.

B. nbsp;nbsp;nbsp;50.38' AIvelAKeft2i445inbsp;fèmiflïs. 2 5.19, ej us T ang. Co mpl.

C. 54.12' LBvclBMeft2ii35^2 .

fcmiilis.2 7. ö’jCjusTang.Compl.

Add.

5^

54

50

I

21

07

24

8

N C veie O eft 195417 D .205.10'nbsp;nbsp;nbsp;nbsp;52I2lt;JOn

femiffis. I o 2.3 5 ,ejusT ang. Compl. nbsp;nbsp;nbsp;Cfubtr.

PHveiHQ.eft 22^22)

differentia 598938

2 Rad.RV. DA. 24

partesST. i ipjSjó—looooo^—AR.149^51 0 multipl.

AR. 1496^1 0 adXY. 1249Q.

134549

59844

29922

14951

produéf. i858

femiffis feu ttang. ARX.934

5289 0

3144©

ut 1S T ad RV,ita ''Öquot;»? ARTE^u

VtAARXfcuiXYjAR adQXYfcuXY.XY,.nbsp;vel, reliéta communinbsp;altitudineXYnbsp;utiARadXY,nbsp;five ctiam,propternbsp;fimil.A^^STRnbsp;amp;ARX

f98938—100000—rel.triang- ETX.3 34!] t44©/adDXZ.55|8i|780

eritqucXZ. 7l 4l 70

HincfubduaaXZfeu747©exXY feu 1249©, relinque-' tur 502 © pro Y Z latitudine quaefita portionisabfcindendje.

Caeterum cum non abfimilimodo adata qualibet figuraredti-linea portio datx ma^nitudinis abfcindi polfit, aut etiam quas ipfius figurae cercam partem five partes contineat, iineisquibuf-dam duntaxat lateribus parallelis amp; abiifdem aequali intervallonbsp;diftantibus: pliira hac de re afferre fnpervacaneum duximus,pra:-fertim cum materiamhanc nee non determinationes eöfpeifan-tes jam fsepius in Lectionibus noftris Publidsabundèpertrada-

veri-

-ocr page 431-

Demonstrationibvs. 403 verimus, eaque occafione illa multis etiam jam diu innotuiffe cer^ «•nbsp;tófciverimus.

Theorema, quod ad folutionem artificiofiflimam Problema-tis pag. 3 71 ut concefTum fupponitur.

'Cum in rimanda olim folutione Troblematisp-ijt non.'-nulla deprehendijfem, qua ad eandemut concejfa Jiippo-nebantur, eaquepoji commentaries meos in hanc Geome-triam Theoremate ad id Geometricè refoluto corroba^ rdjfem: vifum fuit calculum è quo eandem refolutionemnbsp;tune deprompfi bic in medium ajferre, ac quopaBo idemnbsp;d me Jitpraftitum ed qudpoter o perfpicuitate cuivis obnbsp;oculos pon ere. In quemjinem Jihue re'vocetur The or ernanbsp;jam diBum iind cum illis, qua ad explicationem ejmnbsp;369 ^ 370 ulteriüsfunt allatajnjpiciendm erit dein-cepsfequens calculus.

Aflumpto quaefi-to uc vero, hoe cft,

C A eflè ad A F, ficut C B ad A Gnbsp;ducatur porró D Lnbsp;parallela A B, fc-cans C A ,¦ C B in Mnbsp;amp; N, ac occurrensnbsp;ipfi G H in L, po-naturque D A ZOJ.

Deinde calculus fic procedat

Ex aflumptione eft CA AF CB AG

// jdb

e——d-

Exfimilitudiaea’quot;™'quot; BAC amp;AIGeft BC CA AG GI

dh

b-c—— ~ / adlt;af. VndelKcrit Goc—pro qua

brevitatis causa fcribatur^ Et apparet ex hac affiimptione GI inveniri eequalem F A^

'Ete a nbsp;nbsp;nbsp;item-

-ocr page 432-

404

GI IA--dlii-

Exhypothefieft BA AE BC

AD

CO/

•temque CA AB

1 *

Ex fimilitudi-ne AramC AB

A E.tf J

ff-

EI.

CA AB KI

ca—ƒ/ ad IB. * 1

. Imiu ExnaturaEllipfis,peri7.3“‘ ^nbsp;nbsp;nbsp;nbsp;Conicorum Apollonii,pro-

y nbsp;nbsp;nbsp;portionaliafunt

cdFAC coGKH qDAG oCKB

feu, rcjeélis communibus altitudini-bus AC ,G K j amp; A G, C K EA KH DAnbsp;nbsp;nbsp;nbsp;KB

d—— a:-j-igt;IC.

aElB/i-^±^ nbsp;nbsp;nbsp;dc~cx-

hoe eft, reftitutis valoribus ipfa-rum/ amp; z.

A___i_r„.. amp;

fcuC'

“ nbsp;nbsp;nbsp;cc

VndeKHfeuA:, per 16'. 6^'*,

nt CC-feu —-

ce nbsp;nbsp;nbsp;c e

add.IK./.

Denique cxnaturaElli-pfis,per 17.3'“ Conicorum A|)ollonii,

cnGIH eft ad nziF AC.

Seii,propter reólasG I,F A, fupra xquales,

IH ad AC,ut ccEIB ad CZlEAB

-ea.

cef-i~adf nbsp;nbsp;nbsp;ceaf adaf

Et fit, multiplicando turn medios tum extXQmoSyAc e a a d zOd c e aa d.nbsp;ld quod ajTguit, cum aftumendo quaefitum tanquara concef-fum percalculum hunc Geometricum adverum conceflumde-venerimus, qusfitumillud, quod cum hoe conceftb omnimodenbsp;conneditur, efle quoque verum. Quod erat oftendeadum.

^orro ut int elligatur,qua rat tone ex hoe ealculo fupra-diEia refolutio a me dedu^a fuerit: baud gravabor eun-demiakulum Mc ulteriüs it a dij^onere, diBamque refo-•lutionem illid latere Jic adhtbere, ut cuivis fedulohac infpicienti enucleate appareat ^ quijham inter ilium ^nbsp;hanc refolutionem mutum confenjm exijfat. 'Preefertimnbsp;mmhujus refolutionü inventio deinde mihi anfam, com-plures alias demonflrationes Geometricas conficiendi.

-ocr page 433-

Xgt; e' M o N S T R A T I o N I B V S. 405Juhminiflraverit y atque ipfa etiam arüficitm detexijfenbsp;mihi vtfafit,quo Veter es,in multis difficilioribus demon-jirationibus concinnandis, ujïfmt. ^i quidem id mice-jiuduiJdfe njidentur ,quo fua invent a eorumque demonftra-tionespoft er is majori admirationifor ent,ut modum, quonbsp;ea ipfa invenerint ac demonftrationibus. muniverint ynbsp;prorfus fupprimerent amp; abfconderent^


Exaflumptionc CA AF CB AGnbsp;c——d—-—bl ad ^


Etpermutandoper ilt;J. 5 CA CB AF AG


¦^/ad-

C


Ex fimilitudine Aquot;™ BAC,A1G BC CA AG GI

b-c-^ / adlt;^.


Et convcrtcndo per Cor. 4. j CA CB GI AG


Quoniam igiturfupponitur C A effe ad A F, ficut C B adnbsp;A G; erit etiam permutandonbsp;C A ad CB.ficut A F ad A G.

lam quia, ex fimilitudine A'“'quot;BAC amp; AIG,B C eft ad.nbsp;C Ajficut A G ad GI; amp; con-vertendo C A ad C B , ficutnbsp;Glad AG : erit A F per^.^quot;

Quiahïcexaffumptionerepe- nbsp;nbsp;nbsp;SCqua-

litur G lexpriroiperean- lis. Ëodem dcm quantitatem quam 1

AF, coUigiturindtipfas'^°do SCqua-

scqualeteflè. nbsp;nbsp;nbsp;igs eruntE A

Haudfecuszqualeseiunt „ x/r EAamp;DM.nbsp;nbsp;nbsp;nbsp;amp;JJIV1.

Ee e 3 nbsp;nbsp;nbsp;Ex


-ocr page 434-

4o6 nbsp;nbsp;nbsp;De

Ex hypothefi BA AE BC

CONCINNANDIS

Porro cumexnatura A Dnbsp;nbsp;nbsp;nbsp;Ellipfis ? F A C fit ad

¦ hl ad« zoy

? G K H, feu, proptec reftarutnA C, GKx-Ex natura Ellipfis, per 17. 3Conico- qualitatem,F A ad K H,nbsp;rum Apolloniinbsp;nbsp;nbsp;nbsp;ficut CU D A G ad

OFAC [=iGJiH cziDAG cziCKB cziCKB, h.e., propter

dc--cx-j/i.-^bz.—Z.Z. xqualitatem redarum

H.e., rejedis communibus altitudinibus AG,CK,ut DA ad KB; A C,GK; amp; AG,C K,nbsp;nbsp;nbsp;nbsp;amp; quidem ratioD Aad

FA KH DA KB KB, compofita fit ex

d - X -* j-hz. nbsp;nbsp;nbsp;ratione D A ad C B feu

Et reftitutisiprarum^ amp; ?. valoiibus nbsp;nbsp;nbsp;E A ad A B, amp; ex ratio-

FA nbsp;nbsp;nbsp;KFInbsp;nbsp;nbsp;nbsp;DAnbsp;nbsp;nbsp;nbsp;KBnbsp;nbsp;nbsp;nbsp;ne CB adKB feu C A

d-

nbsp;nbsp;nbsp;ad IK: erit quoque ra

ceb - ......^fb fita

ex ratione E A ad

- lt;*ƒ A B, amp; ex ratroac C A

ad I K. Ideoque ciim

, nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;_nbsp;nbsp;nbsp;nbsp;ratio compofita ex ra-

IamutexElementisconftet,qaopa-^j^^^ E A adAB, amp; ao ratio iplius D Aad KB m fimplicilTi-nbsp;nbsp;nbsp;nbsp;C A ad IK,

misterminis expnmipoffit, cumviail-^^^ ea , quam habet lam inveniendimultiplicationeper cru- ?CAEadaKI AB'nbsp;cem(quemadmodumyulgofit)omnino ^^j^nbsp;nbsp;nbsp;nbsp;/

fit Algebraïca: calcduna hic apponam F A ad KH ea. e quo ipfe D A amp; K Brefultant.nbsp;nbsp;nbsp;nbsp;? C A E

tio F A ad K H compo-

KH

ce

FltATX -•

ce

BA AE BC

ad ? KI, A B.

** nbsp;nbsp;nbsp;^ blz^~^ VbiapparetjCum in

c •—ƒ— b! ad EA AB

CA IK BC KB uttaque hac proportionis regula idem ter-fb minus B C ipfis A D amp; K B prascedat,quod ratio ipfius AD adKB, perhujus BC in-terpofitionem, fit compofita ex ratione ADnbsp;^nbsp;nbsp;nbsp;nbsp;^nbsp;nbsp;nbsp;nbsp;ad B CfeuE A ad A B, hoe eft, eadlt;i, amp; ex

CA nbsp;nbsp;nbsp;IKnbsp;nbsp;nbsp;nbsp;ratione B C ad KB feu C A ad IK, hoe eft,

Z1.6.C ¦ ƒ cad/. Acproinde,cumratioexhiscompo-CdCAE cdKI.AB fita, per 2 3. (S’, fit eadem rationi, quam habet

£e-'af nbsp;nbsp;nbsp;iiiiiCAE ad cz!Kl,AB,feu ce ad a/lerit quo-

que

-ocr page 435-

Demonstrationibvs. 407

que ratio ipfius F A ad K H feu ad at eadem , quam habet EUC AEadcn KI, ABjfeu flt;?ad(«/

Ad com- Efto jam p aran dam KI ad F A,nbsp;I H cum ficut lineanbsp;AG,quia, O ad CA.nbsp;inveiita Vnde, af-

KHooquot;-^,

quot; A E pro

ad K Had- communi

di prius altitudinc,

debet IK eritKlad

30/, ut ha- FA, ficut

beatur IH ? fub O

202^/, amp; AE ad

c e hoe

fed pafio

* IZD CAE.

ra-

Erat au-

tem F A ad

Tgt;,-----# nbsp;nbsp;nbsp;_______

tio iplllis

erit ut KI adKH, ficnbsp;CD O, AEnbsp;ad CD KI,nbsp;A B; amp;pernbsp;compofitionem rationis converfam K Inbsp;-HK Hfeiinbsp;I Had KI,,nbsp;ficut CD O,nbsp;AE CDnbsp;KI,AB, adnbsp;CDOjAE.

Sit

ÏH ad A C non fatis commode videtur Geometricè ex- ^ CAE plicabilis: qusfiviprius rationem ipfiusI HadIK;indenbsp;per compofitionem rationis converfam, amp; per alias deni- ^ g Qua-que comparationes venio adrationemipfiuslHadAC, gxaÈquonbsp;utfequitur.nbsp;nbsp;nbsp;nbsp;-

EftoKI atf FA, nbsp;nbsp;nbsp;KH

ƒ—- ci.......X

ut O ad CA.

3* if-c

? KIjAB ...af

Muit. perAE.e.........e

hoe eft, ut oOjAEadoCAE •C€

Vnde exsC^up amp; per compofitionem rationis converfam erit

VtKI KHfeulH ad KI,

fic CD O,AE cdKIjA B ad cdO,AE.

ccf

r

ƒ ---— ƒ

-ocr page 436-

40 8 IHnbsp;f x


De c o n c I n n a n d 1 s


Sit


KI

• ƒ-

ut O


ad


ad


AC, - cnbsp;P.4*


Muit. per A E. e......... e

hoe eft,

aO,AE c3KI,AB utcDO,AEadaP,AE

cef adf nbsp;nbsp;nbsp;* cef_cce


Deinde fit Ut KIadAC,itanbsp;O adP. Vnde,nbsp;aflumptd A Enbsp;pro communinbsp;altitudine, critnbsp;Klad A Cjfic-ut o O, A Enbsp;ad ? P, AE.nbsp;Sed ut I H adnbsp;KI, ita eftnbsp;CU O, AE


d ............ d^ nbsp;nbsp;nbsp;^

Vnde ex aequo erit ut IH ad A C, ita ? 0,AE cilKI,ABadc=lP,AE.

SedutlH ad A C, ita quoqueeft propter redas IG amp; F A fuprasquales Qu^propter ex aequo

^ ^......fa nbsp;nbsp;nbsp;erit ut IH ad A C ;Ec

per i.6'.CClGlHadci]FAC,hoceft,per C30,AE [:=]KI,AB IJ. 3quot;‘Conic.Apoll.jUtüEIB adcnEAB ^d Cd P,A E. Cum ve-(^uocircaeritutcdOjAE oKI.AB rö#urfus , ut ante,nbsp;ad Cd P, A E, ita CdE IB ad CdE A B.nbsp;nbsp;nbsp;nbsp;oGlH fit adoFAC,

ficut Cd E I B ad Cd E A B; amp; quidem IG amp; A F, ut fupra,aequa-les fint oftenfae: eritquoquel H ad A C, ficut CdEIB ad CdEAB. Vt autem IH ad A C, fic quoque crat Cd O; A E 4-Cdl KI, A B adnbsp;Cd P, A E. Quocirca erk ut Cd O, A E Cd KI, A B ad CdP, A £nbsp;itaCdElBadCdE AB.nbsp;nbsp;nbsp;nbsp;•


Fiat jam ut A E ad A B, ita KI adnbsp;Q^:critqueCdKl,

Fiat jam, ut A E ad A B, ita KI ad Q.

T- 5

r , nbsp;nbsp;nbsp;af

g-a ~ ƒ /

eritque per 16.6. cdKI,ABxcidQjAE. aB sequaleCdQ^, Adeoqueutnbsp;nbsp;nbsp;nbsp;a E. Hinc ut

CdO,AE cdKr,AB,feuQ^,AEadcdP,AE,aO, AE plus

hoe eft, rejeóda eommuni altitudine A E, nbsp;nbsp;nbsp;CdKI, AB feu Q,

utO CL ad P, fieCdEIBadaEAB.AE adcdP.AE;

hoeeft,deftruen-

de nbsp;nbsp;nbsp;dnbsp;nbsp;nbsp;nbsp;cc

do communein

akitudinem A E, ut O Q^ad P, fic Cd EIB ad Cd E A B.

Explieita itaque eft ratio, quam habet Cd GIH ad Cd F A C,' quippe oftenfa eft eadcra quse ipfius IH ad A C, feu O -KQ_ad P-

Quo-*

-ocr page 437-

409

Demonstrationibvs.

Quocirca jam ratio explicanda reftat, quae eft inter o EIB amp;n3EAB.


Qiioniam autem inhac explicanda ad 4quot;dimenfiones afcen-ditur, deveniendum erit ad pauciores dimenfiones, ut tota refo-lutio duntaxat per redarumaut planorum confiderationem ab-folvatur.


EI feu

E A AI

EA

rf4- ad

c

...... *quot; e

13.5

IB

AB

af

c

--- a

oElBleu ? luLj E A AI in IB~~HëAB'

ceaf-^ada f

- ------


Vt EI feu EA AI eft ad EA,


Muit, per CA. c.......

ftc CU E A, C A CD AI, C A eft ad CD C A E! ce ad


^ nbsp;nbsp;nbsp;^ A,propter fimilituLe..

A^“'quot;CABamp;AMD,ubiCAeftadAB,

^ars II. nbsp;nbsp;nbsp;pff


Porró quoniamnbsp;ratio Cd’*nbsp;EIB adnbsp;CCEABnbsp;compofi-ta eft exnbsp;rationenbsp;JEIfeuEAnbsp; AI adnbsp;EA,amp;exnbsp;rationenbsp;IB ad AB;nbsp;amp; qui-dem E Anbsp; AI adnbsp;EA, fi


gt;

com-*


-ocr page 438-

410 De concinnandis

ficut A M ad MD feu E A fcribamr cnB A M, communis ficut[Z]BAM oCAIadiir]BAM. affumatural-VclrurfuSjfiproCHCAI,propterfimilitudincm titudo C A,

fit ficut cciCAE,feunbsp;BAM, nbsp;tdC AI feunbsp;BA, Gladnbsp;c^CAEfeunbsp;BAM, hoenbsp;eft , reliu-qtiendonbsp;communemnbsp;altitudinemnbsp;BA, ficutnbsp;AM G Inbsp;feu G L ad

videfu- A™” B A C amp; A IG, fcribatur CU B A, G I, tamI*° ficutcciBAM oBA.GladccBAM,nbsp;hoceft,nbsp;nbsp;nbsp;nbsp;ficut AM4-Gl,hoceft,GLad AM.

relidacom-mutiialtitudineB A,

Vt IB eftad AB,

......a.

c

Muit. per C A

ita CD IB, C A eft ad CC] C A B. afnbsp;nbsp;nbsp;nbsp;CA

Vel ,fi pro Cd 1B, CA, propter fimiluudinem A™quot;* C A B amp; KI B,fcribaturcC] KI, A B,

LnoX fic[=]KI,AB,adl=lCAE,hoceft,reliaa AM^ atverè

* * communi altitudine A B, ficut KI ad CA.

( nbsp;nbsp;nbsp;ficut cdIB,

C A feu KI, ABadccCAB, hoe eft, deftruendo communem altitudinem A B, ficut KI ad C A: Erit quoque ratio cd'‘ E I B ad cd.EAB, hoe eft, ipfiusO Q. ad P,, compofita ex rations G Lnbsp;ad A M , amp; ex ratione KI ad C A.

Conftat igitur, rationem Cd'* E I B ad ccE A B feu ipfius O Q^ad P efl'e compofitam ex ratione G L ad A M, amp; ex ratione KI ad C A.

lam quia fuperior ratio ipfius O Q_ ad P niilli rationi Imea-rum, qusinEllipfi dudsfunt, refpondetj neque etiam adhuc luculenter patet, earn, fi cum ratione G L ad A M, aut KI ad C Anbsp;confertur., ex his compofitam efle,, quemadmodum ex affumptisnbsp;jam fuit dedudum ; fiat praeterea ut

Denique fiat ut KI ad Q^, ficF A adR:nbsp;eritque cc KI, R ae-quale Cd Q., F A. Acnbsp;proinde cuaiO Q.

adP,

KI ad Q^,ficFAadR

‘d! nbsp;nbsp;nbsp;(?*

e

f-

.tï.

critque,per

oKIjRdocdQjFA.

-ocr page 439-

Demonstrationibvs.

F ^


4II



VtO Q^eft adP,

C C

“ nbsp;nbsp;nbsp;7


cf, ‘’f

7 7


Muit. per FA. ......d


ad P, afliimcndo communem al-titudinemF A,fitficiitcliO,F A feu KI, C A, Q^, F A feu

KI,


ücaOjFAieuKIjCAj aQjFAleuKI.ReftadcziPjFAfeuDCA. Rad

daf nbsp;nbsp;nbsp;r-lP,

F A feu ? CArErit rationbsp;compofita ex ra-tione G L adnbsp;AM, amp; exratio-nc KI ad C A ea-*nbsp;dem rationi


Videfupraad notam 3 *


Cf


¦CC


Cur CU P,F A fit CD CT] C Ajita concluditur 3* EftnamqueK I ad FA,utOadCA;


ƒ-i-

Sc couverten do

FA ad KI, d--ƒ.


Ut CA ad Ó.

__if nbsp;nbsp;nbsp;‘J,

7..... d

Vnde ex iquoerit

ut F A ad C A , ita C A ad P. quot;

d--c--c


CA

’KS KI,CA aKI, Pnbsp;nbsp;nbsp;nbsp;R ad ? CA, hoe

eft, eadem rationi,qu3e componiturex rationenbsp;KI ad C A,amp; ex ratione C A -I-R ad C A.nbsp;Ideoqüe fi com-


CD”


Ac proinde, per 17. cd P,F A cX) P C A. munis auferatur Fff anbsp;nbsp;nbsp;nbsp;KI


-ocr page 440-

De


CONCINNANDIS

CA ratioKIadCAjCritquo-

- c que reliqua ratio G L ad

CA AM* eadem reliquae ra-tioni C A R ad C A hoc ^nbsp;nbsp;nbsp;nbsp;eft, erit GL ad AM, ut

CA R ad C A. Quod verum efle deinceps ficnbsp;oftenditur.

Hinc cum ratio G I H ad ? F A C five ipfius IH ad A C eadem fit oftenfa quse ipfius O Q^adP, amp; hxc rurfijs eademnbsp;.rationT, qua; componitur ex ratione KIad CA, amp;exrationenbsp;C A 4- R ad C A; at veró ratio EIBadcziEAB eadem ra-tioni, qux componitur ex ratione GLad A M, amp; ex ratione KInbsp;ad C A: feqiiitur,fi ratio CZ]'‘ GIH ad en F A C(quemadmodumnbsp;fuppofitum fuit) eadem fit rationi cn'‘ ElBadcnEAB, ratio-nem compofitam ex KI ad C A, amp; ex ratione GA 4- R ad C Anbsp;debere quoque eandem effe rationi, quse ex G L ad A M, amp; exnbsp;KI ad CA componitur. Aeproinde, fi iitrobique communisnbsp;auferatur ratio KI ad C A, rationem reliquam»C A 4- R ad C Anbsp;eandem quoque fore reliqus rationi G L ad A M.

Hocautem cumnondum perfe evidens fit, fiipereftutipfum fequenti argumentatione refolvamus atque penitus manifeftumnbsp;reddamus.


412,


23.cgt;.


CA R

ad


oK I,C A cnKIjR

j.,daf

Cf ---


? CA


¦cc


Exfimilitudine nbsp;nbsp;nbsp;ABCamp;MDAeft

AB AC MDfeuAE MAfcuIL

a—c........ e/ ad~. \^dcGLfitQ0lt;^4-'

Ex fimilitudine ABCamp;IAGeft BA AC AI IGfeuAF

ad nbsp;nbsp;nbsp;,

a——c- — ¦ - d

C

Ac proinde, per i(?.(?“, en B A FCDCZ^C AI. Ex fimilitudinenbsp;nbsp;nbsp;nbsp;GLDamp;AMDeft

GL ad AM, if-


ce


Quo-niam e-nim,propter fimi-litudinem triangu-lorumnbsp;GLDamp;nbsp;AMD,nbsp;eft ut GLnbsp;ad A Mnbsp;ita D Lnbsp;feu E I adnbsp;DM


-ocr page 441-

413

413

D E M O N S T R A T I O N I B V S. ficut D L feu EI ad D M feu E A;

ad

^ 7

muit. per CA.f..........c

D M feu E A ; utnbsp;autem

ficut? EI,CAfoTCAË CAIfeu AE,RadaCAE.E f i.i-**nbsp;nbsp;nbsp;nbsp;’nbsp;nbsp;nbsp;nbsp;.nbsp;nbsp;nbsp;nbsp;,nbsp;nbsp;nbsp;nbsp;EAjita,

nbsp;nbsp;nbsp;-j—~— affump-

hoceft, relidacommunialtitudinet:^ com-

AEficutCA RadCA. munial-

Ex conftruftione eft KI CL fa

ƒ—‘4—lt;'/

titudinc

CA, OEI, CAfeu CAE plus CU CAInbsp;feu A E , R eft adnbsp;cn C A E : Erit ut G Lnbsp;ad A M, ita CD C A Enbsp; cuR, A E ad anbsp;CAE, hoc eft , de-ftruendo communemnbsp;akitudinem A E , ficnbsp;C A -f- R ad C A.

R

ad

e

o.

quot;ƒ

c

R

ad

Vide fiipta ad notam

AB KI —a-fi

AB FA

itemcjue AE

Vide fupra ad

notam s * nbsp;nbsp;nbsp;^ —

Ideoque AE per 11. e —

Acproindeper nbsp;nbsp;nbsp;A Food! A E^I-

Hinc cum CH B A F etiam fit GOdl C A I,erit fimilitcr O A E, RgochC AL

PatetitaqueGLeflead AM, ficutC A RadC A, Vt erat propofitum.

Quare cumhocpafto, afiumentes quEcfitumtanquam verum, per refolutionem Geomctricam devenerimus adverumeoncef-fum: fequitur, qusefitum illud, quod cum conccffo ifto omnimode conneiftitur, verum efle. hoc eft, umbram baculi C, qua:nbsp;tranfibat per A, tranfiiflê fimilitcr per B. Quod erat demon-ftrandum.

Et hac quidem,qua Refolutionem GeometricamTheo-rematis concernunt , quod ad folutijiem Rrohlematis f ag.yj-i. ut concejpum[upp^itumfiiit. Caterim quoniamnbsp;its, qui cum Logicisflatuunt ex falfs etiam pojfe verumnbsp;concludi, refolutio h£C adquafiti oftenfionem incerta vi-deri pot eft: placuit major is certitudinis ergo idem T heo-rema Synthetice verificare , procedendo d conceffis ndnbsp;quafta, proutad hoc meinftigavit praftantijfrnus ac

Fff 3 nbsp;nbsp;nbsp;wide-

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414 nbsp;nbsp;nbsp;De c o n c 1 n n a nd I s

wndeqüaque doBijJimm juvenis ‘D. Tetrm Hartjingius, laponenjïs, quondam in addifcendis Mathematis difci-pulus mem folertijjimm.

Demonjiratio autem ipfafilüm calculi fequitur, quails extatpag. 370,ateodemnonnihilhicimmuta-to ; ut appareat pajjim artificium, quo fingula Geome-tricè explicari queant.

Quoniamigkurex hypothefi eft B A adnbsp;A E, ficut B C adnbsp;AD: erit fujjnbsp;extremis BA, AD «

aequale ?'« fub rae-diis B C,A E. Deinde quoniam ex natu-ra Elliplis eft , ut

?DAGadoCKB,

five, rejeftacommu-ni altitudine A G vel C K , ut D A adnbsp;kb, ita F A Cnbsp;ad

Pofita, ut ante, A D 00 ƒ

eritut B A ad A E, ita B C ad A D

a--e -bj ad^fc

ac proindcper i5. dquot;

? BA,AD, cnBCjAE

agt; nbsp;nbsp;nbsp;a ynbsp;nbsp;nbsp;nbsp;ZO be.

ExnaturaEl- nbsp;nbsp;nbsp;tgt; , •

Conicorum

Apollonii

Upfis pet 17 KJj.y nbsp;nbsp;nbsp;XB. ^

AG.c AGvclCK c

efl: O D A G.y z. ad tinCKB. bz.^zx.^

V K. d nbsp;nbsp;nbsp;KH. a;

. AC.c^ AC vel KG. c ut aP A C. TZad CDiGKH. £x.

-ocr page 443-

De M o N S T R A T I o N I B V S. 415'.

# nbsp;nbsp;nbsp;AG AC ad ? G KH, id eft,re-

li(5ta communi altitu-dine A C vel G K, ita F.A ad K H j amp; qui-demD AadKB.fiBAnbsp;pro communi altitu-dine fumatur,fitnbsp;ad^. ^ ficutcnBAjADnbsp;feu « B C, A E

id cft,rejedis communibus altitudinibus zamp;c,

* eritutD Aad KB jitaF A ad K H y. . ^—-3;.-4/ ad X.

BA

five,affumendo cotnmunem altitudinem a,

‘xbaz.-

vel

¦d!

utllIiBAjADfeuaBCjAEadcrjBA.KBjita F Aad KFi X ay

ad cdB A,K B : erit ut oB C,A E ad O B A,K B,ita.F A ad K FI, EftojamKIco/*

Porró cum ex fimilitudincnbsp;Aram B 'C A amp;nbsp;BKI, BC fitnbsp;ad Ca, ficutnbsp;B K ad KI: eritnbsp;[ZnfubBC ,KInbsp;aquale fubnbsp;CA, BK. Ea-dem rationenbsp;cum B C fit adnbsp;BA, ficutBKnbsp;ad B I: erit CUnbsp;fub B C , B12-quale cil‘“ fub

BA, Bk.

Haud fecus cum fimilia fintnbsp;A'quot; BCA amp;nbsp;AGI, acidcir-co BC ad CA,nbsp;ficut A G adnbsp;G I: erit CU fubnbsp;B C,. G I sequa-lecu'^fub C A,nbsp;A G. Similiternbsp;cum B C fit ad'

-2: / ad ƒ feu nbsp;nbsp;nbsp;. ac proinde

eritque propter fimilitudinem A'™quot;’BCAamp;BKI utBCadCA,uaBKadKl

b——c-b- ^ nbsp;nbsp;nbsp;^

u UT r~,— aBC.KI, aCAjBK

add.HK.x quot; per 1^.5-

pcrIG, 4 i '’f

D einde fit IG CO nbsp;nbsp;nbsp;-

ïnGlU.fh hx

eritque propt.fimil. A™quot;'B C A amp; A G1 u t B C ad C A, ita A G ad GI

y-c-z, ! ad^ feu^j. ac proinde per

Similiter efto A Ico^-eritque propter fimil. A™” BCAamp;AGInbsp;ut B C ad B A, ita A G ad A1

cuBCjIG aCAjAG

bh ZO cz..



-ocr page 444-

4i6 D e ut B C ad B Ajita B K ad BInbsp;b——a-


CONCINNANDIS

? BA, ficut A G ad A I : erit pa-ritcr O fub B C,


b—zj ad /feu nbsp;nbsp;nbsp;proinde per


? BC,BI oBA,BK y bl TD ahaz..


A I scjuale CD*® fub AB, AG.



R'--

Ex naturaEllipfisper i7.3*“Conic. Apollonii eft ? F A C ad O GI H,utcnEAB ad cdE IB

cd —^— hf hx-ae/ ad b^l el.

Eft autemj)er 23. ratio FACadcnGlH

cd-hf hx

compofita exratione FAadlHfeuIK KH, amp; d---—ƒ X

cx ratione C A ad GI, id eft, aflumendocommu-

£-h

BC

nem altitudinem é,cx ratione o’‘

/3

B C,C A ad CD B C, GI vel ? C A, A G, five, rcje-

bc - bh nbsp;nbsp;nbsp;feu cz.

CA

(ftacommunialtiuidinec, ex ratione BC ad AG.

lam vero, quia cx natura Ellipfis cdnbsp;FACeftadcDGIH,nbsp;utcDEABadcciElB;nbsp;amp; quidem ratio cd'‘nbsp;FAC ad CdGIHnbsp;compofita fit ex ratione FA ad IFi feunbsp;IK K H, amp; ex ratione CA adGI, idnbsp;eft, affumendo com-munem altitudinemnbsp;B C, ex ratione cd’*nbsp;BCjCAadaBC,nbsp;G I ycl |3 CD C A ,nbsp;A G, five etiam , re-Simi-

-ocr page 445-

Demonstrat ionibvs.

Similiter ratioCZ3‘‘ EABadcuEIBcompofitaeft ae-kj ^l

4t7

jeóta communt altitudine CA,nbsp;ex ratione B C adnbsp;AG; At ratio o''nbsp;EABadaEIBnbsp;compofita ex ratione E A ad IB,nbsp;amp; ex ratione^ A Bnbsp;ad EI ; quarumnbsp;quidem E A adnbsp;IB, fi B C pronbsp;eommuni altitudine fumatur, eftnbsp;ficutcztBC, E A

€X ratione E A ad IB, amp; ex ratione A B ad EI.

e-1 nbsp;nbsp;nbsp;A

Quarum quidem E A ad IB, fi B^C pro eommuni e-1 nbsp;nbsp;nbsp;b

altitudinc fumatur, eadem eftquse ö'

BC, E AadtnBC.IBfeuaB A,BK,hoc eft,ea-ye —------------ . bl vel abaz.

y

4em qu2 F A ad K H.

d-X

Sed AB ad E I,fi B C fimiliter pro eommuni altitu-A — nbsp;nbsp;nbsp;b

dine fumatur,cadem,quae ?'* A B, B C ad CZIB C,E I ad cnB C, IB feu

Ab- bks^be nbsp;nbsp;nbsp;yCDBA, BK,

ê nbsp;nbsp;nbsp;et,nbsp;nbsp;nbsp;nbsp;qqa: eadem o-

vel oBCjAIjid eft,BA,AG, C3BC,EA velcmBA, fténfa eft S ratio-five nbsp;nbsp;nbsp;AZ. Ajynbsp;nbsp;nbsp;nbsp;niFA ad KH;

A D, hoe eft, reliöa eommuni altitudine A B, feu fed A B ad EI, fi eademquïBCadAG-f-AD.nbsp;nbsp;nbsp;nbsp;BC fimiliter pro

b - z. y- nbsp;nbsp;nbsp;eommuni altitu-

Erit igitur ratio compofita ex ratione nbsp;nbsp;nbsp;dine fumatur, ut

pera 3 .(J“,ratio[r3''FA,BCadorK,AG oKH,AG, ad ? B C,AI vel

FAadlK-4-KH, amp;ex ratione B C ad A G, id eft, ? A B, B C, ad d--f x nbsp;nbsp;nbsp;b-z. nbsp;nbsp;nbsp;? B C,E I,id eft.

t BA, A G, ca B C, E A velnbsp;«caBA,A D,fi-

ve etiam , reliöa

eommuni altitudine A B , ut B C ad -A G -H A D :nbsp;Erit ratio com

bd

eadem rationi quae componitur ex ratione F A ad KH,

d--X

eadem rationi, quam habet ca F A, B C ad ca K H, A G ca KH, A D,nbsp;bd---xz xy.

amp; ex ratione B C ad A G A D, id eft, per 2 3, b--z. y

pofita ex ratione F A ad I K-f-K H,amp; ex ratione BC ad AG,ideft, per 23. (Jquot;, ratio ca'‘ F A, B C ad ca I K, A G-|-ca K H, A G,eadem rationi,quxnbsp;componiturexFA adKH,amp; ex rationeBCadAG-t-AD.ideft,per 23.^quot;,nbsp;eadem rationi,quam habet oF A,BCadcaKH,AG ci]K H, A D.nbsp;Pats II.nbsp;nbsp;nbsp;nbsp;^ g g

-ocr page 446-

418

Hinc cum

aFA,BC,fitadalK»AG oKH,AG,ficutidemaFA,BCad Hinc

--— fsu xz--bdt cumCD

oKH, AG cuKH, AD; erit, per5gt;. f‘, nbsp;nbsp;nbsp;FA,BC

ad nbsp;nbsp;nbsp;xz.-^xi/‘.nbsp;nbsp;nbsp;nbsp;ad CZ] IK,A Gh-

OIK,AG l=lKH,AGiq.l=lKH^G aKH.AD.

a? nbsp;nbsp;nbsp;dcmhabeatra-

tionem, quami-

Vnde, dempto utrinque communi a'® K H, A G, dem ? F A, BC

xz. nbsp;nbsp;nbsp;ad CZ! K H, A G

erit quoque reliq. CZllK , AG aequale reliquo

i=3Kh’ag

KH, AD nbsp;nbsp;nbsp;aequale CD*® KH,

xy nbsp;nbsp;nbsp;AG a'®KH,

Acproinde , per i lt;5'. nbsp;nbsp;nbsp;quibus

ut IK ad K H, ita D A ad A G. nbsp;nbsp;nbsp;“ commune au-

ƒ- nbsp;nbsp;nbsp;-j/ ad s. nbsp;nbsp;nbsp;feratur czdKH,

AG, erit quoque

KH, ita DA ad AG.

reliquum czi IK, A G sequale reliquo o’® K H, A D. Vnde erit ut IK ad

Sed

-ocr page 447-

419

Sed ut I K ad KH, ita cft, af-fumpta commu-ni altitudine B C,nbsp;a IK, BC velnbsp;^a C A, B Knbsp;ad aKH.BC.nbsp;At ficut D A ad

Demonstrationibvs.

BC

Scd ut IK ad KH, ita eft, aff coram. altit. f--

r

al K,B C vel aC A,B K ad aK H,B C. bfnbsp;nbsp;nbsp;nbsp;cbcz.-bx.

AB

A t D A ad A G,ita aff. comm.alt. 4, eft cnD A, A B ^ G, ita, aflumpta


communi altitii-dine A B,aDA, ABvel«nnBC,nbsp;A E ad a A G,nbsp;A B. Quare eritnbsp;utaCA,BKadnbsp;aKH,BC,itanbsp;aBCjAEadanbsp;AG, AB. Cum

aj

yeloBC,AE ada AG, AB. be -

Quare erit ut

aCA.BK adaKH,BC,itaaBC,AEadaAG,AB. cb‘—‘CZ.bx - ^ e / ad az.-

S nbsp;nbsp;nbsp;BC

CutnautemfuprafitFAadKH,i.e.,a{r.comm.aIt.^, autemfupra fitd,

d_a; • nbsp;nbsp;nbsp;utFAadKH.fi-

aFA,BCadaKH,BC,ricutaAE,BCadaKB,BA, ve,aflumpta com-

bd - bx -be! ad ab — az., quot;^uni altitudine

Foc eft, convertendo nbsp;nbsp;nbsp;BC,aFA,BC

aKH,BCadaFA,BC,ricutaKB,BAadaAE,BC: adaKH, B C,

bx — .....bd--abaz. I ad be'. itaaAE,BCad

EruntaCA,BK aKH,BC aFA,BC tres magni- CD K B, B A ; id

cb — cz.-bx.......bd tudines ab eft, convertendo,

amp;I=:]KB,BA aAEjBC aAG,AB tres alis ab F A,B C, ficut

abaz......be-az, altera par- CI]KB,BAada

te,qu£Ebi- AE,BC:erunt

una parte, C3KH, B C ad

ab

una

amp; a KB


ns fumpta: in eadem ? C A, B K, ? funt ratione , qua- KH,BC,amp;anbsp;rumque proportio FA,B C 3 magni-eft perturbata:nbsp;nbsp;nbsp;nbsp;tudines

parte.


BA, oAE,BC,amp;aA G, A B tres aliae ab altera parte, quac bina fumpta in eadem funt ratione , quarumque proportio eft perturbata.

Ggg 5 nbsp;nbsp;nbsp;Quare

-ocr page 448-

Pi Q\ob.


4^o De concinnandis

Quare eciam per 23. 5quot; exjequalitateproportionales Vnde Sc ipfae ex «ï'untnbsp;nbsp;nbsp;nbsp;jEqualitate pro-

id eft, o C A, B K adcD F A, B C, ficutdl K B, B A portionales c-c^'cz.——hd--ah—az. runt


BA

ad cn A G, B A, feu, rej. com. alt. lt;«, ut K B ad A G. --az.............bz. ¦ X..


, nimirum, erit ut ? CA,nbsp;BK ad ? FA,nbsp;B C, ita ? K B,nbsp;BA ad cziAG,nbsp;BA, id eft, reli-(fta com muni al-*nbsp;titudine B A , ita


Idqmdconvenit cum £(juatilt;me invent» pag. 371, mtltiplicmdo fc. turn extremes turn medios termines, ojlendens nos in eodemnbsp;calculo Giometric'e explicando eo perveni(fe, ubinbsp;ebzezzaquatur b b dbdi,.

Deniqueutinveniatur A Gfeut, quoniamfumen- nbsp;nbsp;nbsp;De-

do C A feu c pro communi altitudine ,

K B eft ad A G,ftcut ? C A,K B ad Cl CA,AG bx._‘- - z. ——— cb-cz. / ad cz.'~nbsp;eritut


nique, quoniam, afiumpta com-muni altitudfiftenbsp;CA, KB èft'ad


C]CA,BKadciFA,BC,itaoCA,KBadciCA,AG. AG.hcutoCA,


¦b—.


cz.-


¦bd-


¦cb — c?,/ad c?,.


KB ad oC A, A G : erit ut CJ


HinccumciCAjBKadicFA.BCamp;adoCAjAG CA, BKadci


cbcz. nbsp;nbsp;nbsp;bd

fandetn habeat rationem, erit per p. 5'*, ? FA,BC.aeq.C3‘°CA, AG.nbsp;bd 00nbsp;nbsp;nbsp;nbsp;cz,.

Vnde per 16quot;. (J^'erit,

ut C A ad A F, ita B C ad A G.

c-d —— b ! ad

Quod erat propofitum.


FA, BC, itaa CA , KB ad CUnbsp;C A, A G. Quo-circa cum teC A,nbsp;B K ad ciFA,nbsp;BC amp; adaCA,nbsp;A G eandem habeat rationem, e-rit c F A , B Cnbsp;xquale Cl‘° C A,

A G; ac proinde C A ad AF, ficut BC ad A G. Quod erat demon-ftrandum.


F I N / S.


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