AC i CC -C(A-i-C<--?,C ct 



A A + AC A^A-t-CJ _ \ B 

 quibus fubflitutis erit 



__ _AA + BB + CC + AB + AC+BC+BCcof.a+\Ccof(3 



+ABcof.y, 

 ibi pcrmutabilitas litterarum efl: manifcfla , ideoque pro 

 omnibus obferuationum ordinibus femper erit 



_ _ V a ^AA+BB+CC+AB+AC+B € +BC cof. « + AC cof.,3 + 



+ ABcof.y) 

 quae formula etiam hoc modo exhiberi poteft 

 _ _ V(aA ? +aB ? +2C J +4ABcof.:y 2 +4AC cof.;(3 : +4-BC cof.a'). 



§. 13. Inuento iam iflo valore quantitatis irrationa- 

 lis a tam finus quam cofinus angulorum Cp, Cp' et Cp" fe- 

 quenti modo exprimentur: 



fin. (£> _I A ( 1 — coj. 7 ) -t- C ( » — cof. a ) . CQ f (fj __ A/ri.-y — Cftn.a . 

 fin. Cb' — Bfi— co/.a)-(-A( ■— .eoj.p) . CQ f tfy __ B /7n. a — ,\/;a, 3 . 

 fin (£" _Z C ( ■ — cof. (3 -t- B ( » — co/. 7 ) • qq{ (N/ — Cr.j} — Bfn.7 



§. i+ Ex his iam formulis triplici modo valor 

 litterac q elici potefl, qui autem terni valorcs inter fe per- 

 fccte congruere dcbebunt , id quod (latim ex primo valore 

 q — +, _~r^ peripicietur _ cum enim ex fonnulis modo 

 inuentis fit 



COf. CfV - COf. <£> — B'/ B . g ~A(f> B .P-»- r K'>)-f-C.7-.tt ob 



B -+- C __ - A erit cof. $' - cof. Cp — - ^ 1 "-^^^ 01 } 

 ideoque ? _r - ___£___ , „bi permutabilitas iu oculo$ 

 incurrit fimulquc patct ex benis rcliquis formulis 



Q B et n C 



" ca\. $" — cqj. p tl 7 coj.$ — coj. $■' ' 



prorfus eandem hanc exprcflioncm refultare debuiffc. 



§. 15 



