If $f : R \to R$ be given by $f(x) = \tan x$, then $f^{-1}(1)$ is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $\frac{\pi}{4}$ ##
Given that, $f(x) = \tan x$
Let $y = \tan x$
$\Rightarrow x = \tan^{-1} y$
$\Rightarrow f^{-1}(x) = \tan^{-1} x$
$\Rightarrow f^{-1}(1) = \tan^{-1} 1$
$= \tan^{-1} \left( \tan \frac{\pi}{4} \right) = \frac{\pi}{4}$ $\left[ ∵\tan \frac{\pi}{4} = 1 \right]$
$[∵\tan^{-1}(\tan \theta) = \theta]$