Question
Differentiate the $\tan ^{-1}\left(\frac{\sin x}{1+\cos x}\right)$ w.r.t. x.

Answer

Let f(x) = tan–1$\left(\frac{\sin x}{1+\cos x}\right)$. Observe that this function is defined for all real numbers, where cos x $\neq$ – 1; i.e., at all odd multiples of $\pi$. We may rewrite this function as
f(x) = tan-1$\left(\frac{\sin x}{1+\cos x}\right)$
= tan-1$\left[\frac{2 \sin \left(\frac{x}{2}\right) \cos \left(\frac{x}{2}\right)}{2 \cos ^{2} \frac{x}{2}}\right]$
f(x) = tan-1$\left[\tan \left(\frac{x}{2}\right)\right]=\frac{x}{2}$
$\Rightarrow$ $f^\prime(x)= \frac12$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free