Topic: Signals and Systems
Let delta(t) denote the delta function. The value of the integral from -a to a of delta(t)*cos(3t/2) dt is
- A. 1
- B. -1
- C. 0
- D. pi/2
Answer: A. 1
Explanation: Using the sifting property of the Dirac delta function, integral from -a to a of f(t)delta(t) dt = f(0) as long as the integration interval contains t=0. Here, f(t) = cos(3t/2). Evaluating at t=0 gives cos(0) = 1.