Answer
a) $x$ is in the interval $(-\infty,-2) \cup (2, \infty)$.
b)$x$ is in the interval $[-2,2]$.
Work Step by Step
Because the x-axis is basically $f(x)=0$, hence the values above the x axis are such that $f(x)\gt0$, and the value below or on the x-axis are such that $f(x)\leq0.$
a) All the x-values such that the graph is above the x-axis: $x$ is in the interval: $(-\infty,-2) \cup (2, \infty)$.
b) All the x-values such that the graph is below or on the x-axis: $x$ is in the interval $[-2,2]$.
