Solution (source code)

= Solution

The factor $x^2$ is an <even function> and $\sin x$ is an <odd function>, so their product is an <odd function>. Its <definite integral> over the symmetric <interval> vanishes:
$$
\boxed{0}.
$$
Indeed the <substitution rule> $x=-t$ changes the integral over $[-\pi/2,0]$ into the negative of the integral over $[0,\pi/2]$.