Question
$\sin (\tan^{–1} x), | x | < 1$ is equal to

Answer

Let $\tan^{-1} x = y,$ then $\tan y = x$
$\Rightarrow \sin y = \frac{x}{\sqrt{1+x^{2}}} $
$ \therefore y = \sin^{-1} \left(\frac{x}{\sqrt{1+x^{2}}}\right) $
$ \Rightarrow \tan ^{-1} x=\sin ^{-1}\left(\frac{x}{\sqrt{1+x^{2}}}\right) $
$ \Rightarrow \sin (\tan^{-1} x) = \sin \left(\sin ^{-1}\left(\frac{x}{\sqrt{1+x^{2}}}\right)\right) $
$= \frac{x}{\sqrt{1+x^{2}}}$

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