Answer
(a) $zeros$
(b) $zeros$
(c) (Refer to image for chart)
(d) $(-2,0)$ and $(1, \infty)$
Work Step by Step
We find the irreducible factors and find all of the real zeros of the polynomial using those real zeros.
We use those real zeros to set up intervals, and find the signs of the polynomial using test points on those intervals.
As the sign of the polynomial $P(x)$ is positive on the intervals $(-2,0)$ and $(1,\infty)$,
$P(x)\geq0$ on the intervals $(-2,0)$ and $(1,\infty)$.