Solve for x: tan−11+x1−x=21tan−1x, x>0.Answer: x=31SolutionFor x>−1, tan−11+x1−x=4π−tan−1x. Substituting,4π−tan−1x=21tan−1x4π=23tan−1x ⇒ tan−1x=6π ⇒ x=tan6π=31This satisfies x>0.x=31CBSE Class 12 Board · Subjective