Question

Let f(x) = sin 2x + cos 2x and g(x)=x2-1, then g(f(x)) is invertible in the domain

• A. $x\ \epsilon\ [\frac{-\pi}{2},\frac{\pi}{2}]$
• B. $x\ \epsilon\ [\frac{-\pi}{4},\frac{\pi}{4}]$
• C. $x\ \epsilon\ [0,\frac{\pi}{4}]$
• D. $x\ \epsilon\ [\frac{-\pi}{8},\frac{\pi}{8}]$

Answer 1

Answer: (D)

$x\ \epsilon\ [\frac{-\pi}{8},\frac{\pi}{8}]$

Answer 2

The correct answer is (D) : $x\ \epsilon\ [\frac{-\pi}{8},\frac{\pi}{8}]$.