igitur fit in Triangiilo Q O -N, iln. N Q - fin. Q O. (in. N O Q, 

 'ii facilitatis gratia exprimatur Q O per e, POQperO et 

 QON per g, eric 



■fin. c — fin. e. fin, e ~ fin. ^. fin. ( 1 80' — $ — (3) n 

 fin. e. fin. (^ +/3} r fin. ^ (fin. ^. cof. |3 -^ cof ^. fin. |3) z:^ 

 ftn..f. fm. (cof. p H- cot. ^. fin. ^). 

 >\tqni in Triangiilo P O Q eft , fin. Q O. fin. P O Q =z 

 fin. P Q. fin. O P Q, fcii (in. e. fin. $ — fin.^. Jfin. <x, tumque 



■ ^r\t- "A cot.b.fm.a — cof.a.coj.x 



COt. f_ j^^ — . 



His igitnr valoribns fubftitutis, prodibit fequens aequatio : 

 *fin. <: - fin.i». (cof p. fin. a. H-fin. p cot, b. fin.df-fin.p.cof a.co(.a), 



ideoque 



-(^ - cot. b. fin. a. fin. |3n fin. a. cof (3. — cof a. fin. |3. cof <3. 



Quare fi ponatur tang. ^, cof. a — tang. 5, fiet 



jin^col^.r^jin^ ^ ^ _ ^ J 



jin.b.coj, (i, • • O y 



■hincque 



cjaj/..,p-co/^;^_aJ^P_) — fin. ( a - 5 ) , 



J'fi. b. coj. (3. V / ' 



■vnde ob cognitos valores ipforum a, b-, ^, |3, J, innotc- 

 fcet angulus a. 



§. 4. Pro cafu fpeciali, quo b — a , formula ali- 

 quanto fiet concinnior; erit enim 



%'b ~ ^i"- (^- cof. b — fin. a. cof (3 — cof a. fin. (3. cof. ^, 

 Afbi quidem , fi angulus a valdc fit exiguus , ita vt ftatui 

 queat cof. aiz: I, fiet 



g^^ =r fin. «. cof (3 , hinc fin.a=;^^p, 



-quae formula cum fuperius allata congruit , fi loco fin, Cy 

 AMa Acad. Imp, Sc. Totn. 111. P. i. N n fin. 



