Tìm X ( e j ω ) biết x ( n ) nhân quả và x ( n ) = e n

$X\left(e{}^{j\omega }\right)=\frac{1}{1-e{}^{\left(1-j\omega \right)n}}$

$X\left(e{}^{j\omega }\right)=\frac{e{}^{\left(1-j\omega \right)n}}{1-e{}^{\left(1-j\omega \right)n}}$

$X\left(e{}^{j\omega }\right)=\frac{1}{1-e{}^{j\omega n}}$

$X\left(e{}^{j\omega }\right)=\frac{e{}^n}{1-e{}^{-j\omega n}}$