{ 28-i ) 



in which we must therefore calciüate — . From (o;) ui the torin 



dv 



follows : 



{l-{-.iii)Lb — (f{v—b) 



d3 f , d^\ , d<p 



dv \ dv I dv 



db (7,i 



because — z= Ah — according to (ö). 



dv 



dv 



Hence 



(v—b) -^^-if -\-{x^if)Lh — (y) 



dv dv 



d3 

 So we have to calculate — , and that from (1"). This relation, dif- 



dv 



ferentiated logarithmically, yields : 



/? ' 1 — ^5 l+ojjiy dv dv if dv 



x-\-l dij X -\- <f dip 



/?(1—,?)(1 +,!•,?) dv " (f dv ■ 



If in this we substitute the value (y) found just now for 



or 



d(p 



dv 



, we get : 



.r + 1 



di3 



dii 

 — (p + {x-]-(p)Lby- 



x-x-(p dv 



or 



or also 



',^l-^){\+X^)dv 



x^l 



^ 



V — h 



{x^ifY Lb 



X i- (p 



d^ 



Jv \j{l—^){l^X^) "^ ^ V- b] " V—b ' 



v — b d^ '«H-y 



i. e. taking {a) into account : 



V — b d[i x-\-(p 



V — b 



l-\-x[3 dv x-\-l 



/?(l-i?) 



+ i^+^pY 



for which we ma.j also \vrite 



