transibunt in has : 



V ' it —2t cos'2$ • - 



2i / 2dv (* 7 - 1 ) co. & •/<• — coy 2~9 



7 it — £« cos 2i-t-l '/' " 



§. 19. Tantum igitur supereft", utloco dv valo* debi- 

 tus fubftituatur. Cum igitur iit iw zz , " - "" 1.-, erit diffe- 



rentiando 



4 t>ai; = _££pf^g*_^ ideoque 



■ (t — cos2 _J* ' * 



3l> ___: (^ — 2 t coy -S> -+ -i)df ]_j2 



*^~tt Xit-M- CUS_S , )_ 



hocque valore in trod ncto fiet 



t — -. sw3 f dtvrn t 



y /2 ' Vi-t-i (t — cos2&) ' 



2» Ifoja / , a____£_T_JL_ . 



^ V 2 ' VfTT (t — cos 2 2>) ' 



quarum formularum integratio nulla amplius laborat diffi- 

 cultate, quandoquidem facile ab omni irrationalitate libe- 

 rari pofsunt. 



j. 20. Tantum enim opus eft -poni y/EEJ -»- u . tum 

 enim erit t_=£Liti', ideoqne 

 t - cos 2 9- =_ «J-_____ _-__-*__t-L__J__H_- ~= ^»^»4-2^9. t ver0 



UU — I „„ I 7 " 



erit ^t — — -**.____. , quocirca erit 



[UU — 1)4 J * 



^-~rv = ~ -—4 — ssr—o ex quo ambae noftrae for- 



t — cos2$ (ttu — i)(au nn9 2 r- cos 92)-' T. 



mulae ita prodibunt rationaliter expressae ; 



■t „ • o. _/ , r - « ^ - 



^ - Sin ^ ^(_m — I)(u_sm&«4-.~ Fs^ 



_V — cosS-i/zf d - . 



' J (uu — II (uu sin &* 4- cos S»»> * 



quarum ergo integratio per regulas notissimas facile expe- 

 duur. 



$. ai. 



