(a) Find the possible values of x for which \(\sin^{-1}(x^2 - 1) = \frac{1}{3}\pi\), giving your answers correct to 3 decimal places.

(b) Solve the equation \(\sin(2\theta + \frac{1}{3}\pi) = \frac{1}{2}\) for \(0 \leq \theta \leq \pi\), giving \(\theta\) in terms of \(\pi\) in your answers.