(a) Solve the equation \(\sin 4 x=\frac{1}{2}\) for \(0 \leqslant x \leqslant \frac{\pi}{4}\), giving your answers in terms of \(\pi\).

(b)

The diagram shows parts of the graphs of \(y=\sin 4 x\) and \(y=\frac{1}{2}\). Find the exact area of the shaded region enclosed by the curve and the line.