For part c it seems like the ZT doesn't exist. Anybody get the same thing or am I doing it wrong? -Pjcannon 23:11, 23 February 2009 (UTC)
I think the answer is exactly same as part b answer except that the ROC is $ z < \frac{1}{3} , z > 1 $--Kim415 00:33, 24 February 2009 (UTC)
I agree with PJcannon and Kim415, since there is no union between the ROCs, then it's null such that there is no ROC for the signal --Mlo 15:18, 24 February 2009 (UTC)
