1. The problem asks to find the value of the function $f$ at $x=0$, i.e., $f(0)$, by analyzing the given graph. 2. From the description, the graph has a line/ray crossing the y-axis at the point $(0, -6)$. 3. Since the y-axis corresponds to $x=0$, the value of the function at $x=0$ is the y-coordinate of the point where the graph crosses the y-axis. 4. Therefore, $f(0) = -6$. 5. This is the value of the function evaluated graphically at $x=0$.