z-Transform Example- Determine the z-transform X(z) of the causal sequence xn]=a"un] and its ROC NowX(=)=∑am]z=∑a"z n=-0 0 The above power series converges to X(z)= for az<1 1-az ROC is the annular region z> al Copyright C 2001, S K MitraCopyright © 2001, S. K. Mitra 10 z-Transform • Example - Determine the z-transform X(z) of the causal sequence and its ROC • Now • The above power series converges to • ROC is the annular region |z| > || x[n] [n] n =   =   =   = −  =− − 0 ( ) [ ] n n n n n n X z n z z , for 1 1 1 ( ) 1 1   − = − − z z X z