Question

Determine the product of two signals: x1 (n) = {2,1,1.5,3}; x2 (n) = { 1,1.5,0,2}.

(a) {2,1.5,0,6}

(b) {2,1.5,6,0}

(c) {2,0,1.5,6}

(d) {2,1.5,0,3}

I got this question in final exam.

Question is taken from Discrete Time Signals in portion Signals and Systems Basics of Signals and Systems

Answer 1

Correct option is (a) {2,1.5,0,6}

Easiest explanation: Product of discrete-time signals is computed element by element.

⇒ x(n) = x1 (n) * x2 (n) = {2×1, 1×1.5, 1.5×0, 3×2} = {2,1.5,0,6}.