Answer
Refer to the image below for the graph.
Work Step by Step
Note that $f(x)=y$.
Thus, the given equation is equivalent to $y=-4$.
RECALL:
The graph of the equation $y=k$ is a horizontal line.
Every point on the line has the same y-value.
Thus, to graph $f(x)=-4$, you can plot the points (0, -4), (-3, -4), and (3, -4).
Then, connect them using a line.