Inverse Trigonometric Functions Question 12

Question: If $ A={{\tan }^{-1}}x $ , then $ \sin 2A= $

[MNR 1988; UPSEAT 2000]

Options:

A) $ \frac{2x}{\sqrt{1-x^{2}}} $

B) $ \frac{2x}{1-x^{2}} $

C) $ \frac{2x}{1+x^{2}} $

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

Given that $ A={{\tan }^{-1}}x $ Now $ x=\tan A\Rightarrow \sin 2A=\frac{2\tan A}{1+{{\tan }^{2}}A}=\frac{2x}{1+x^{2}} $ .