Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. If $\tan ^{-1}(x+1)+\cot ^{-1}(x-1)=\sin ^{-1}\left(\frac{4}{5}\right)+\cos ^{-1}\left(\frac{3}{5}\right)$, then $x$ has the value

Inverse Trigonometric Functions

Solution:

$\tan ^{-1}\left(\frac{x+1+\frac{1}{x-1}}{1-\frac{x+1}{x-1}}\right)=2 \tan ^{-1}\left(\frac{4}{3}\right)=\pi+\tan ^{-1}\left(\frac{-24}{7}\right)$
$\Rightarrow x^2=\frac{48}{7} \Rightarrow x=4 \sqrt{\frac{3}{7}}$.