We are given that: \[ \tan^{-1}(x) = \tan^{-1}\left( 3 - \frac{\pi}{4} \right) \] Since \( \tan^{-1}(x) \) gives the angle whose tangent is \( x \), the above equation implies: \[ x = 3 - \frac{\pi}{4} \]
Thus, the value of \( x \) is \( 3 - \frac{\pi}{4} \).
Prove that:
\( \tan^{-1}(\sqrt{x}) = \frac{1}{2} \cos^{-1}\left( \frac{1 - x}{1 + x} \right), \quad x \in [0, 1] \)
Find the principal value of:
\( \cos^{-1}\left(-\frac{1}{2}\right) + 2\sin^{-1}(1) \)