⑩天掌 Teaching Plan on Advanced Mathematics o 二、f(x)=e[p(x) cos ax+ P sin ax]型 f(x)=e[ P cos ax+ P sin ax利用欧拉公式 e te lax e P 十 2 2i +-n)el+io).r )e (-i)x 22i 22i =P(x)eo)x+P(x)e(-0), 设y”+py+qy=P(x)ex1o),n1=x"gn (+i()x tianjin polytechnic dmivendityTianjin Polytechnic University Teaching Plan on Advanced Mathematics f (x) e [P cos x P sin x] l n x    = + ] 2 2 [ i e e P e e e P i x i x n i x i x l x      − − − + + = l n i x l n i x e i P P e i P P ( ) ( ) ) 2 2 ) ( 2 2 ( +  −  = + + − ( ) ( ) , ( i ) x ( i ) x P x e P x e +  −  = + ( ) , ( i ) x y py qy P x e +  设  +  + = , ( ) 1 i x m k y x Q e +  = 利用欧拉公式 二、 f x e Pl x x Pn x 型 x    ( ) = ( )cos + sin