= io 7 ===== 



$. 8 8. Quod fi jam has determinationes ad formulas 

 integrales, quas pro litteris p,q,r, etc. invenimus, transfera- 

 mus, quoniam invenimus z = J/d(p cos X$(i + 2 cos (p)% si 

 exponenti n fuccessive valores tribuamus o, 1,2,3, 4 etc. 

 quia feries Z a poteftate x x inchoare eft censenda , for- 

 mula differentialis ^(pcos A(p per hanc feriem geometricam 

 multiplicari debebit: 



(1+2 cos(p)°x x H-(n-2cos([)) I x x+I -f-(i-+-2cos(I)) 5 x x+2 -+-etc. 



cuius fumma eft _, qua ergo in calculum 



I — x — 2 x cos (p 



introducta fumma quaesita Z ita exprimetur : 



rj ,1 C x x d(pcosA(p ra$=ol ,. 



Z~|/ -S -^- ,!■ , ubi quantitas x 



eft conftans. 



§. 89. Quoniam igitur hic invenimus iftam fummam 



v K 



>/(l — 2X — 3XX)" 



v K 

 fcil. Z zz Pz/ zz — — , existente 



v zz 



I — x — V (I ■—2XJ—-3XX) 



nunc hujus ipfius formulae integralis valorem adeo alge- 

 braicum exhibere poterimus , quandoquidem nunc novimuseife, 

 1 f x x 3(pcos Xj ) 2A 



W V I— X— 2XC05(p " ]/(l — 2X — 3 3tx) 



five multiplicando per -^- habebimus 



x x 



/* 3(pC OSA(p __ 7T f V Y 



J I— X— 2XC0S(p }/(i-2X-3XX)\X/: 



O 2 §. poi! 



