) 34+ ( ^'^^* 



_t e' 'ctr «a — nf.it^) — t — ^ ' — i — fe^ — . c)* 



a (c coj.(Ji — c' coj. (P'] (ccoj.(J) — c':o/. (JH]^ * 



ideoque multiplicatione per (c coC. — c' coL ^'f inflituta: 

 '-f (cof. (p - cof. 0') (<r cof. (p - (t' cof. (p) 

 r= ( f cof. (t) - <:' cof. (J)')'- - {c' - r)', 

 quae aequatio in hanc euoluitur: 



^' (c cof. C|)= - (<r + f') cof. Cp cof. Ct)' + t-' cof. (J)") 

 = 2rf'(i-cof. (PcofCpO-^^Tin.Cp^-f^Tin.^y, 

 Cue quod codem redit in iftam: 



~<i(ic-{-f')(i-coi:.(pcof.(^')-cCm.(p'--c'{[n.<^'*) 

 z= a t-f' (i-cof (p cof.(t)') - <:' fm. (J)' - c'' fin. p\ 

 Ponamus nunc cfTc (p -\- (p — t et (p' — (p=:(5, crit 



cof. (p cof. (p' := i cof. 5 — : cof. e , 

 tumque 



fin. (p-- - i-nH^^^ ;-: cof.(£-5)= :-i (cof.e cof.J+fin.e fin.5) 



€t 



fin.(p'' = -~"/--:^ = :-:cof(H-^)-:-:(cof.£Cof.Q-fin.£fin.^). 



Quum igitur per fupcrius inuenta fit: 



2 f f (^:±ii - 2) ( I - cof (p cof. Cp') - 2 c' C|^- i) fin. (J)* 

 _;f"(L- i)fin. (p"zro, 



pro cof (|). cof (J)', fin.(I)' ct fin. (J^'= fuffcdis corum valo- 

 ribus, ad hanc pertingcmus aequationem : 



c c' (i^-£' - 2) (2 - COf. (^ - cof. 0' 



— f' ('-' — i) (i — cof £ cof. — fin. £ fin. $) 



— <," (i-— i)(i -cof £cof.(J + fin.£fin.O) = o. 



Ex hac autcm aequationc dcducitur, 



{C - c) 



