Question

exp[jwn] is periodic

(a) for any w

(b) for any t

(c) for w=2pi*M/n

(d) for t = 1/w

I have been asked this question in class test.

I would like to ask this question from The Complex Exponential in portion Signals and Systems Basics of Signals and Systems

Answer 1

Correct answer is (c) for w=2pi*M/n

To elaborate: Discrete exponentials are periodic only for a particular choice of the fundamental frequency.