1 1 vote The signal $x_{n}=0$ for $n<0$ and $x_{n}=a^{n} / n$ ! for $n \geq 0$. Its $z$-transform $X(z)=\sum_{n=-\infty}^{\infty} x_{n} z^{-n}$ is $1 /\left(z^{-1}-a\right)$, region of convergence $\text{(ROC)}$: $|z| \leq 1 / a$ $1 /\left(1-a z^{-1}\right)$, $\text{ROC}$: $|z| \geq a$ $1 /\left(1-a z^{-1}\right)$, $\text{ROC}$: $|z|>a$ Item $(a)$ if $a>1$, Item $(b)$ if $a<1$ $\exp \left(a z^{-1}\right)$, $\text{ROC}$: entire complex plane. Discrete-time Signals tifr2012 discrete-time-signals z-transform + – admin 277 views answer comment Share Follow Add Sync Questions Print 0 reply Please log in or register to add a comment.
