*•>¥.% ) 80 ( §.'c|^- 



exiftente V fiindione quapiam ipfius x, et difFerentiatione 

 fajfla prodire: 



habebitur 



dV.x-^-ddX-\-^^dX-^ifX' + Q^X~^X\ 



hincque 



dV^x^^iddX-^-^^dX-^dX^ + ^X-^X^). 

 Liquet autem effe 



Jx^ddX = x^dX-'Kfx^-' dXdx, 

 tumque 



/x^^dX — x^^X-X/x^^-^Xdx, 

 quare erit: 

 /x^ddX=zx^dX-\x^-'Xdx-{-X(X-i)dx/x^-'Xdx'y 

 p^/jc^ dX- (i^ x^X --K^^ /x^-'Xdx', 

 ^/x^X^dx — (ix^X^-X^/x^-'X^dx; 

 ideoque iam prima integrationc difFerentidlia ddX tt dX* 

 cx calculo eli(a funt ; tum vero dtnuo integrando facilc 

 liquet differentiale dX penitus elidi. 



*""' RECHER^ 



