*->S4| ) 349 ( §-?2<- 



Vt ex hac aeqiiatfone valor ipiius c' faltem proxime de- 



terminari que^t, ponamus: 



fln. a' — fin. a — 5 cof a; cof a' — cof a-\~ $ Cn. a\ ' 

 fin. b' rr fin. ^ 4- e cof ^ ; cof. b' — cof b — e fin. ^ ; 



vbi h — "K (a — a') ete — h^b^ — b), fuppofitis praeterea 



cofinibus arcuum a — a' y b' — b vnitati aequalibus. His 



igitur valoribus fubftitutis, fiet 



cof <r ( I - 5 cot. a -H e cot. b ) -f- IpL-^ -'^ — cof c', 



\ / ' Jm. a Jin. b 



Tumque fi pro cof c' - cof czz: 2 fin. ('-^= ) fin. ('-^), 

 adhibeatur "K^c — c') fin. c, obtinebimns: 



c-c'=zia-a>)C^^fs^)-^ib^b'){^^:^^n. 

 iam vero eft 



COf B ZZ: "'•■&-ca/-.c^ g^ ^^p^ Q _ coU-cof^bc£c 

 Jin.cim.a Jtn.ciii.b ' 



hinc erit c — c' — (a — a') cof B -f- (Z» — ^'] cof C , plane 

 vt antea. Caeterum corrediones , quae produda (a — a')', 

 (b — b')'^ et {a — a'){b — b') inuohiunt , nunc quoque ra- 

 tiocinio analytico erui pofl^ent, verum quum calculus hunc 

 in finem inftituendus, ahquanto prohxior euadat, eum heic 

 miffum faciamus. 



§. 9. Regrediamur igitur ad formulam : 



C — c' ( a — a') ( '^''^•b-coS.ccof.a ) _ ( Ll __ L) ( cof.a — co f.beor.e ^ 



V J\ fm.cjin.a ' \ M Jm.cjin.b h 



pro qua ponamus 



a — a'-\-b' — b — \k. et a — a^-^-b — b' — Vy 

 eritque 



V. ^/ 1 u, ( ^^- ^■^"*- ^ — ""^- a /«""• a — cof. c I f i n. b cof. a — fin. t cof. h ) \ 



' r" \ jin.aftn.bjin.c / 



I « j/ / cof. bfin. b -4- fin. a cof. a — cof. c {fin. b co f. a -f- lin. a cof. b ) \ ' 



» ^ (in.ajin.bSin.c ~ )' 



Quum nunc fit, 



a fin. b cof ^ = fin. 2 ^, 2 fin. a cof a — dn. 2 a, 

 fin. ^ cof a — fin. a cof ^ =: fin. (^ — «) 

 fin. b cof. a 4- fin. a cof ^ — fin. (^ 4- «) , fiet 

 Xx 3 (^- 



