Mathematics

Problem

The value of

\tan^{-1}(1) + \cos^{-1}\left(-\frac{1}{2}\right) + \sin^{-1}\left(-\frac{1}{2}\right)

is equal to (a)

\frac{\pi}{4}

(b)

\frac{5\pi}{2}

(c)

\frac{3\pi}{4}

(d)

\frac{13\pi}{12}