quae forma contrahitur in iflam: 



2 T fm. ^ y =: cof J - cof (y -^ -f- 5> 



Cum aiitem fit ynLl5, erit /fey — 2«7r, idcoquc 

 cof (k y H- 5) — cof. ^, vmie fit 

 aTfin. ^y — o, ita vt nunc fic 

 2 S fin. 5 y =: 2 TT fin. (; y -. ^), ideoque, 



S — ^ ^'"- (jy-^) 



fin. ^ y 



Eft vero lyiz:^ et 5 = y, ideoqwe 



^y-.5~!Li!Li:i)-!L5, ob & zr .TT - Jf , 



f[ fin. -*? 



Iiocque modo habebimus S — — , coafequ&ater yator 



fin. "-^ 



integralis quaefiti concluditur fore 



2;rfin."^ _ 2?rfin."feg ^ 



^ fm. Oli^^'^ ^ fin. 7} fin. ^* 



ynde formetur fequeas Theorema, 



Theorema L 



§. 47. H^^c fonnula iiiiegyaas: 



- x''-''-f-x''-^^| d_x 



I -H 2 X* cof ;; 4- x'" ° x 

 c temino x =r o «y^^^tt^ ad x — 00 extenfa , producU hune 



lyalorem: ^^ '"• t , ^ui adiungatur adhuc fequens. 

 A fin. "ij fin, ^ 



Theo- 



