I20 



Qtiod si aiitcin formiilam illam integralem 



(i — ncoi^')^ \f ' 1 — n^OiT^ I" ( i — Fi COI. 0)^/ * 



attentius consideremus , mox peispicicmus , ejus intégrale, 

 quod sit A, necessario esse debere hujus formae: 



. a.sin.i(p , p <in. (Pco^ . i tp 



Inslituta autem difTcrentiatione reperietur 



à^ iacos f$ Xa n j/n. Cî>î;n. iCp , (i cos.^Pcos i ^ 



3 I s;n. 4) s;n. i(p (X H- i ) i'^ « :"i- '35'_f '^- *_$ - 



(i^— tTcos.^)^-^ """" ("i — Ti'coî. $}>>•-+-- 



Quoniam i^itiir in nostra formula integranda non inest 

 sin. /($), mcmbra luinc sinum continentia se mutuo toUcre 

 debent, id qnod evenit sumendo Xa?irr: — (3i. Sit igiUir 

 a rz: i et |3 .izi — Xn^ et intégrale siippositum erit 



. 7 sin i (J) X ïi s;n. Cp co?. I $ 



(i — n COS. (p)-^ (i — ncDS. (p)^"^"' 



dilTcrenliiile vero 



dA ;' ;■ oç. 7'CP Xn coî.:^) cas. f^) ■ X (X+On^ s ;n.$° co ?.i(p 



ô$ ( I —ncoi.(p)^ "(i — nlos (p)^-+^ ' (i — 71 COS. (p)-^ -t- - 



Qiiodsi nLinc hoc differentialc coinparcmus cum for- 

 mula illa integranda 



/coj. r(p g COS. cp eof. ! 45 fo cos. <p2 cos. 7"^ 



(7^ 7rC0s"(P}^ 1" (7^ 71 COS (p)>^H^ I (^^^'iTcOS.'^)''^-*-^ 



ex hac comparatione émergent valorcs quaesiti /, g, h. 

 Ante autem quam cani instituere licct, in postremo mem- 

 bro loco sin (p- scribendum est i — cos. (pS q"0 facto 

 istud membrum ad hanc formam redncetur : 



X(X -f- 1)71^(1 — cot ^-)coi.i(^ •' '0 ^ t (P 



■ (i — n cojlp)^'--*-'- ^ . — I. cj, P',^ 



t coî (p cor. ; Cp , c c o: ^- cof <$ 



~h (i — T7o$7^/^^ "T" (i — n cos~(p)^-+^ * 



