a (cof. ^ C cof ^ (A - B) 4- cof. ^ (A + B)) 

 = 4 cof. \ C cof -; B cof. ; A. 

 Hoc igitur valore fubflituto prodit 



2 fin. i A fin. -; B fin. ^ G 



§. 15. Pono heic quoque obferuari meretur effe 



cof ; CA + B - C)z:cor -;(A + B) cof. ; C + fin.; (A+B;fin.;C 



-2fin.;t-Ccor.:(g+/;) + cofYg-^))^^'''-^^'''-^^~'''-^''^-'^-'''^'''-^^-''' 



= \. - —z — i— — yfin. s fin.(-f-«) fin. (s-b^ fin.(j-0 



fin. tf fin.^ fin.c v • v • v y 



_Vfin. jfiP.(.f— ^)fin (.f~Z')fin.(j--f) 

 2 fin.;a fin.;^ fin.;^ 

 Tum vero et patet quomodo mutatis mutandis 

 cof ; (A - B + C) vel cof. ; (B + C - A), 



pcr Litera triangiili exprimi qucant. Deinde etiam notari 

 conuenit efle 



fin.;(fl+^-0 = 2Qcof.;C(cof;(A-B)-cof.;(A+B)) 

 :=:4Qcof ;Cfin.; Afin.;B, 

 ideoque fiet 



Hn ■ (a^b-cy "^-^"^-S cof (S-A)cof. (S-B ) cof (S-C) . 

 '^^ ^" 2cof ; Aco(.;Bfin.;C 



at mutatis mutandis fimiles formulae pro fin. ;(a — ^ + f) 

 vel fin. \{b -\- c ~ a) adferri podunt. 



Tab. Iil. §. 16. Theorema XI. Si circulo viinori ABD in- 



Fig. 2. jlriptum juerit triavguJuin ABD c.\' arcubus circulorum ma^ 



xiniO' 



