Question Number 16720 by Manish Raj last updated on 25/Jun/17
$${let}\:{x}={tan}\theta\:,{so}\:\theta=\mathrm{tan}^{−\mathrm{1}} {x}\:{given}\:{that}\: \\ $$$$\mathrm{tan}^{−\mathrm{1}} \sqrt{\mathrm{1}+{x}\mathrm{2}−\mathrm{1}/{x}} \\ $$
let-x-tan-so-tan-1-x-given-that-tan-1-1-x2-1-x-