z-Transform In general, the roc of a z-transform of a sequence g[n] is an annular region of the z plane R。-<z< Rg where o≤Rg<R+≤o ROC Copyright C 2001, S K MitraCopyright © 2001, S. K. Mitra 7 z-Transform • In general, the ROC of a z-transform of a sequence g[n] is an annular region of the z￾plane: where −   + Rg z Rg 0  Rg −  Rg +   ROC Rg − Rg +