= C77) = 



aeque r.c piin(rtiim minimi C'', acqtialirer diflciit. Si fiimma 

 arcuiim a ct b qiuidninti fiicrit ucqiuiiis, puii(fta C ct C^inC'' 

 incidunt; fia autcm ^ -h ^ ^ 90% bina puncfla C et C' fiunt 

 imaginai-ia. Vtroque i^itur cafu angulus A C B , qui erat 

 minimus intcr maxima, nuuc iplc fit maximus, aicu AB cius 

 meafurain cxhibente. 



Euolutio cafus 



quo A — 2B. 



Hic cafTis idco attentionc dignus vidctnr, qiiod pofito 

 A~2B fccuridum mcmbrum aequationis cubicac euancfcat, 

 ita vt habcamus tang. c^~-"-. Manifcftum autcm eft ob 



A — 2 B , hoc cft 



fin. a fin. d fin. a' -}- cof. a cof b zzz 2 fin. a fin. b^ fiuc 

 fin. a* n: 2 — cot. a cot. ^, 



hunc cafum locum habcrc non poffe, nifi produdum cotan- 

 gcntium amborum arcuum a ct b intra limitcs i et 2 conti- 

 ncatur, quia aJioquin anguhis a fierct imaginarius. 



9 



Arcubus autcm a ct b ita affumtis, vt cot. ^cot.Z^^-K^i 

 habcbimus pro arcu EC hanc cxprcffioncm: 



tang. z^ -JH^JjlJl^ . At 



'-' ccj. c( j,n. .6-1-11 



cof. u — -/(cot. a cot. b — i) =: /'^j/::-""^ ^*', idcoque 



' ^ ^ ' Jm. j jin. ' ^ 



. 3 (C\n. ^ fin. /' / 



tang. z^ — . . , i . 



fin. {a -\~ b) /cof. {a -\- bj 

 Tum autcm tangcns anguli maximi crit 



tan c. A C B i=r _=f"L/' /"'1'j' — " ''Ji:± — . 



^ 5 11 ■+-Jin. »» , — c Jin. z coj. » 



K 3 Pro- 



