2.柱座标: 1 au aa (P-)+ 0 p dpdp pdp 分离变量(,0,2)=R()y(q)z(=) ΦZddR、RZd2Φ (p,)+ 0 dz 2+A⑩=0 p dr pdr p dz Rdp2R2z么2s2 y h a d()=A cos mo+ Bm sin mo m=0,2. 柱座标： u(,,z) = R()()Z(z) ( ) ) 0 2 2 2 2 2 +  =  +  dz d Z R d RZ d d dR d Z d       ( ) 0 1 ( ) 1 2 2 2 =     +   +     z u z u u       0 2 2 +  =   d d       + + = 2 2 2 2 2 2 dz d Z d Z dR d R d R R 分离变量 a.  = m 2 m = 0,1,2,  () = Am cosm + Bm sin m (x, y,z) r    x y z z h