Cho x ( n ) = e j w n , đáp ứng của hệ thống y ( n ) được xác định như sau:

$\text{y}\left(\text{n}\right)=\text{H}\left(-\text{e}{}^{\text{j}\text{w}}\right)\cdot \text{e}{}^{\text{j}\text{w}\text{n}}$

$\text{y}\left(\text{n}\right)=-\text{H}\left(\text{e}{}^{\text{j}\text{w}}\right)\cdot \text{e}{}^{\text{j}\text{w}\text{n}}$

$\text{y}\left(\text{n}\right)=\text{H}\left(\text{e}{}^{\text{j}\text{w}}\right)\cdot \text{e}{}^{-\text{j}\text{w}\text{n}}$

$\text{y}\left(\text{n}\right)=\text{H}\left(\text{e}{}^{\text{j}\text{w}}\right)\cdot \text{e}{}^{\text{j}\text{w}\text{n}}$