The function $f(x) = tan x- x $ for $x \in \left(-\frac{\pi }{2}, \frac{\pi }{2} \right) $ is :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → increasing function
$f(x)=\tan x-x$
$f'(x)=\sec^2x-1$ as $\sec^2x≥1$
so $f'(x)≥0$
⇒ f(x) is increasing in nature