Question

The period of the function $f(x)=|\sin 4x|+|\cos 4x|$ is

• A. $\pi /2$
• B. $\pi /8$
• C. $\pi /4$
• D. None of these

Answer 1

Answer: (B)

Since, $|\sin x|+|\cos x|$ is a periodic function with period $\pi /2$.
$\therefore f(x)=|\sin 4x|+|\cos 4x|$ is a periodic function with period
$\frac{1}{4}\cdot \frac{\pi }{2}$ i e, $\frac{\pi }{8}$.