The period of $f(x)=\frac{1}{2}[\cos (\sin x)+\cos (\cos x)]$ is :
Answer & explanation
Correct answer: option 2
$f(x+\pi / 2)=\frac{1}{2}[\cos (\sin (x+\pi / 2))+\cos (\cos (x+\pi / 2))]$
$=\frac{1}{2}[\cos (\cos x)+\cos (\sin x)]$
period = $\pi / 2$