Question

Simplify
${\tan }^{-1}$ $\sqrt{2}$ - ${\cot }^{-1}$ (1/$\sqrt{2}$)

Answer 1

Let $\tan x=\sqrt{2}⟹\arctan \sqrt{2}=x$

$⟹\cot x=\frac{1}{\sqrt{2}}⟹arccot\left(1/\sqrt{2}\right)=x$

Hence final result is $=x-x=0$