Mark (√) against the correct answer in the following:Let f(x) = cos-

1.	Mark (√) against the correct answer in the following:Let f(x) = cos-1 2x. Then, dom (f) = ?A. [ - 1, 1]B. \([\frac{-1}{2},\frac{1}{2}]\)C. \([\frac{-\pi}{2},\frac{\pi}{2}]\)D. \([\frac{-\pi}{4},\frac{\pi}{4}]\)
Answer» Correct Answer is (B) \([\frac{-1}{2},\frac{1}{2}]\) f(x) = cos^-1 2x. domain of cos^-1x = [ - 1,1] on multiplying by an integer the domain decreases by same number ⇒ domain of cos^-1 2x = [-1/2, 1/2]

Mark (√) against the correct answer in the following:Let f(x) = cos-1 2x. Then, dom (f) = ?A. [ - 1, 1]B. \([\frac{-1}{2},\frac{1}{2}]\)C. \([\frac{-\pi}{2},\frac{\pi}{2}]\)D. \([\frac{-\pi}{4},\frac{\pi}{4}]\)

Answer»

Correct Answer is (B) \([\frac{-1}{2},\frac{1}{2}]\)

f(x) = cos^-1 2x.

domain of cos^-1x = [ - 1,1]

on multiplying by an integer the domain decreases by same number

⇒ domain of cos^-1 2x = [-1/2, 1/2]