Answer
(a) $(0,1)\cup(2,\infty)$.
(b) $(-\infty,0]\cup[1,2]$.
Work Step by Step
(a) Based on the given graph, we can identify the solution for $f(x)\gt0$: $(0,1)\cup(2,\infty)$.
(b) Based on the given graph, we can identify the solution for $f(x)\le0$: $(-\infty,0]\cup[1,2]$.