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QUESTION
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\item[(i)]
Sketch the region defined by the inequalities:
$$0\leq x\leq\pi,\ 0\leq y\leq2\pi,\ 0\leq z\leq\frac{\pi}{2}.$$
\item[(ii)]
If the region is occupied by a solid $S$ with density at any point
$(x,y,z)$ given by the formula $2xy^2\cos z$, compute the total
mass of the region $S$ by evaluating an appropriate triple
integral.
\item[(iii)]
The region $S$ is divided by the plane $x=ay$ (where $a$ is a
constant $0