例1:从Z变换的变量置换得到 例 X(z)=∑x(m2z1 2=pJ/0 1=-00 X(e/o) z=已10 例1：从Z变换的变量置换得到 例1 ( ) ( ) ( ) 1   j z e n X e X z x n z j = = =  =− −  j z = e 