«73 



::_ j^ ; tang AT — ^^ : unde najjciscunur ting E D =: 

 tang(EF — DF),- h. e. 



tan"' ^ ian gB cqrg -«-fang A co/P . 



*•" O tang»tangA€}JjiCOj^ — I* 



unde fequitur folutio cafuum 11. 2. a. IIi. £. «. (J. xi.): 

 datis nempe ternis quahtitatuin' A, B, a, (3, datur et quar- 

 ta (5. ac). 



5. 22. Eodem modo reperitur (§. 21.) tang A B =: 

 tang(BF'— AF), h. e. 



langy — ,<,f ., „, p _ c<,/ a cTTb ' "^* 

 tangg^ •— • ' ^'/ ^ '""g 3 -+- co/ h tan g g , 



D • 1 — c / A cO/u;oag afangP * 



quae' aequatio offert folutionem cafuum II.- 2. c. III. 2. 6. 

 (5. ir.):- 



§. 23. • In Triangulis orthogonalibus B E F , ' A D F , 

 habemus' 



tnng F'— '-^iiiJgJ — ^""g *■ ^ (S. 13.)^ 



fmFzn^^zr-^iiLAD (5. 15.)^ 



Jtn B F /m A F ^ J* ■' ^ 



— co/F.BF co/DAF (K I8.),' 



co/EF co/Ul' ^•* '* 



imde fequentes " cbtinemus aequationes : 



finEF^JflL^rinDF, cof E F = — ££0 cof D F, • 



icnga ' .f eo/A 



fin B F := '^{-" cof D F, cof B F = — 'il^^ fin D F, 



co/ A ' tang B ' 



fin A F r= '4^ cof D F, cof A F =: ^S^ fin D F. 



coj A ' lang A 



Cnm itaque" pofito i H- tang= A cof^ |3 = R^ fjt (f. ai.)' 

 fin D F z= 'iZLAilP , cofDF = i, 



acquii- 



