Mathematics

Problem

The smallest and the largest values of

\tan^{-1}\left(\frac{1-x}{1+x}\right), 0 \leq x \leq 1

are (a) 0,

\pi

(b) 0,

\frac{\pi}{4}

(c)

-\frac{\pi}{4}, \frac{\pi}{4}

(d)

\frac{\pi}{4}, \frac{\pi}{2}