Let f(x) = √cos x. Then, dom (f) = ?

Question

Mark (√) against the correct answer in the following: 

Let f(x) = √cos x. Then, dom (f) = ?

A. \([0, \frac{\pi}{2}]\)

B. \([\frac{3\pi}{2},2\pi]\)

C. \([0,\frac{\pi}{2}]\cup[\frac{3\pi}{2},2\pi]\)

D. none of these

Answer 1

Correct Answer is (C) \([0,\frac{\pi}{2}]\cup[\frac{3\pi}{2},2\pi]\)

f(x) = √cos x

As per the diagram

We can imply that domain of √cosx

is \([0,\frac{\pi}{2}]\cup[\frac{3\pi}{2},2\pi]\)