2、代入（将（④）代入原定解问题) (x,t)=(x,t)+W(x,t)…(4) u a ax+fx0<<L>0)…0 Vi+Wr=aVs+a'Wg+f(x,t),(O<x<L,t>0) 10+Wl0=4(0,V-+WlxL=4,(0 4xo=4(t),4x=L=42(t)…(2) 4r-o=p(x,9 =o-0 o.v 3、确定W(x,t) Vlx-o+Wlo=4(t) V川x-0=0 →W=40(④ Vx=L+W=L=4(t) Vl-1=0 W1=4,0)…(⑤)2、代入(将(4)代入原定解问题) 2 2 2 2 2 0 1 2 0 0 ( , ),(0 , 0) (1) ( ), ( ) (2) ( ), ( ) (3) x x L t t u u a f x t x L t t x u u t u u t u u x x t                            u x t V x t W x t ( , ) ( , ) ( , ) (4)   2 2 0 0 1 2 0 0 0 0 ( , ),(0 , 0) ( ), ( ) ( ), ( ) tt tt xx xx x x x L x L t t t t V W a V a W f x t x L t V W u t V W u t V W V W x x t t                                     3、确定W(x, t) 0 0 1( ) V W u t x x     V x0  0 0 1( ) (4) W u t x  2 ( ) V W u t x L x L     V x L  0 2 ( ) (5) W u t x L 