112 



THE FUNCTION </> AND 



or 



If w > 4, 



If n 



2 



-<t>d h Vd<f> 1 - 

 6 -d?-fc- 6 



e ' -Tjr-j e 

 de 1 ae 



or 



(368) 

 t(369) 



(370) 



whence " ^- = ^. 



Giving A the values 1, 2, 3, etc., we have 



as already obtained. Also 



* This equation may also be obtained from equations (252) and (321). 

 Compare also equation (349) which was derived by an approximative method, 

 t Compare equation (360), obtained by an approximative method. 



