Question 21
The diagram shows the curve $y = \cos x\sqrt{\sin 2x}$ for $0 \le x \le \frac{1}{2}\pi$. The curve has a maximum point at $M$, where $x = a$.
**(b)** The region enclosed between the $x$-axis and the curve is rotated through $2\pi$ radians about the $x$-axis.
Find the exact volume of the solid generated.
