Browse Questions

# The minimum value of $\cos(\cos x)$ is

$(a)\;0\qquad(b)\;-\cos 1\qquad(c)\;\cos 1\qquad(d)\;-1$

$\cos x$ varies from $-1$ to $1$ for all real $x$.
Thus $\cos(\cos x)$ varies from $\cos 1$ to $\cos 0$
$\Rightarrow$ Minimum value of $\cos (\cos x)$ is $\cos 1$.
Hence (c) is the correct answer.