Special case for inverse tangent sum to \(\pi/2\) for JEE

Formula

\(\tan^{-1}x+\tan^{-1}\left(\dfrac{1}{x}\right)=\begin{cases}\dfrac{\pi}{2},&x>0\\-\dfrac{\pi}{2},&x<0\end{cases}\)

Variables: \(x\in\mathbb{R}\setminus\{0\}\).

Frequently tested inverse tangent evaluation.