Question

The period of the function $f\left(x\right)=2\cos \frac{x\pi }{3}$ is

• A. $6\pi$
• B. $4\pi$
• C. $2\pi$
• D. $\pi$

Answer 1

Answer: (A)

$6\pi$

$\because$ period of $\cos x$ is $2\pi$
$\therefore$ period of $2\cos \frac{1}{3}(x-\pi )$ is =$\frac{2\pi }{1/3}=6\pi$