●●●●●● 续 o(o)+ d JO (o)+-x(o) O 丌6(0)X(o)+:X(o)=nX(0)(0)+ Xlo) JO x()dr4a(0)(l)+x) JO 如果X00,则第一项为零x()dr Xlo OX 第 2 页 jh jh ( ) ( )      e d j 1 π j   − −       = + x ( ) ()     X      = + j 1 π ( ) ( ) ()    X  X j 1 = π + ( ) ( ) ( )     j π 0 X = X + 如果X(0) = 0 ,则第一项为零 ( ) ( ) ( ) ( )       j d 0 X x X t  + − π ……续 ( ) ( )     j d X x t   −