Question

Where h*x denotes h convolved with x, x[n]*d[n-90] reduces to

(a) x[n-89].

(b) x[n-91].

(c) x[n=90].

(d) x[n].

The question was posed to me in class test.

This interesting question is from The Impulse Function topic in chapter Signals and Systems Basics of Signals and Systems

Answer 1

Right answer is (c) x[n=90].

Easiest explanation: The function gets shifted by the center of the delta function during convolution.