Solve \( 3\sin^{-1}\left(\frac{2x}{1+x^2}\right) – 4\cos^{-1}\left(\frac{1-x^2}{1+x^2}\right) + 2\tan^{-1}\left(\frac{2x}{1-x^2}\right) = \frac{\pi}{3} \)
Solution:
Use standard identities:
\[ \sin^{-1}\left(\frac{2x}{1+x^2}\right) = 2\tan^{-1}(x) \]
\[ \cos^{-1}\left(\frac{1-x^2}{1+x^2}\right) = 2\tan^{-1}(x) \]
\[ \tan^{-1}\left(\frac{2x}{1-x^2}\right) = 2\tan^{-1}(x) \]
Substitute into equation:
\[ 3(2\tan^{-1}x) – 4(2\tan^{-1}x) + 2(2\tan^{-1}x) = \frac{\pi}{3} \]
\[ 6\tan^{-1}x – 8\tan^{-1}x + 4\tan^{-1}x = \frac{\pi}{3} \]
\[ 2\tan^{-1}x = \frac{\pi}{3} \]
\[ \tan^{-1}x = \frac{\pi}{6} \Rightarrow x = \tan\left(\frac{\pi}{6}\right) \]
\[ x = \frac{1}{\sqrt{3}} \]
Final Answer:
\[ x = \frac{1}{\sqrt{3}} \]