Answer
$f^{-1}(-3)=-2$
Work Step by Step
RECALL:
(1) If $(a, b)$ is on the graph of $f(x)$, then $f(a) = b$.
(2) If $f(a)=b$, then $f^{-1}(b)=a$
The given graph contains $(-2, -3)$
This means that $f(-2) = -3$.
Thus, $f^{-1}(-3)=-2$.