Question

Assertion (A): The signals a^nu(n) and a^nu(-n-1) have the same Z transform, z/(z-a)

Reason (R): the region of convergence of a^nu(n) is |z|>|a|, whereas the ROC for a^nu(-n-1) is |z|

(a) Both A and R are true and R is correct explanation of A

(b) Both A and R are true but R is not correct explanation  of A

(c) A is true but R is false

(d) A is false but R is true

This question was posed to me during an interview for a job.

I'm obligated to ask this question of The Z-Transfer Function in portion Digital Control Systems of Control Systems

Answer 1

Right answer is (d) A is false but R is true

The best I can explain: Both have the ROC as given in the reason is true but the z transform for the second is with a minus sign.