例 0 0 0 V(x x(-x) +1 y x=0 X=a y=0rla-x sh=x(a-x) wxy)=∑4exp"n!+Bp any nIx 1 sin2 xx yy u u + = − 0 0 x u = = 例 0 x a u = = 0 0 y u = = 0 y b u = = v x y x a x ( , ) ( ) = − 2 xx yy v v + = −0 w w xx yy + = 0 0 w x= = 0 w x a= = 0 ( ) w x a x y= = − ( ) w x a x y b= = − 1 ( , ) { exp[ ] exp[ ]}sin n n n n y n y n x w x y A B a a a     = = + − 