V 024 Ox 0y2az0z Let V2d=4 P aza So we can transform the function VO=O =0 (a) 022022 as y=V2(v2y)=V2P=0 for V2P=0 1111 x y zz  =   +    =     2 2 2 2 2 2 4 P z z =     =   2 2 Let 4 So we can transform the function 0 4   = 0 ( ) 2 2 4 a z z =     as ( ) 0 4 2 2 2   =    =  P = For 0 2  P =