例2 0<t<T 0<t<2T 0 otherwise h0)=10 otherwise y(t)=x(t)*h()= x(oh(t-r)dr x(t-)h()dz如果用图解法做: X(T h(r) x(t-t 2T 2T t-t0 t例2 1 0 ( ) 0 t T x t otherwise    =   0 2 ( ) 0 t t T h t otherwise    =   ( ) ( ) ( ) ( ) ( ) ( ) ( ) y t x t h t x h t d x t h d        −  − =  = − = −   x t( ) − 0 2T 2T  h( )  0 1 t T− t  如果用图解法做: x( ) T