1. The problem is to find where the function $f(x)$ is greater than or equal to zero, i.e., $f(x) \geq 0$. 2. From the graph description, the function crosses the x-axis at points approximately $x = -6$, $x = 0$, $x = 3$, and $x = 7$. 3. The function is above the x-axis (positive) between $-6$ and $0$, and again between $3$ and $7$. 4. The function is below the x-axis (negative) outside these intervals and between $0$ and $3$. 5. Since we want $f(x) \geq 0$, the solution includes the intervals where the function is above or on the x-axis. 6. Therefore, the solution is: $$ [-6, 0] \cup [3, 7] $$ This means $f(x)$ is non-negative for $x$ in the intervals $[-6, 0]$ and $[3, 7]$.