Answer
a) $f(2)=-3$
b) $f(-1)=2$
Work Step by Step
a) When $x=2,$ the corresponding $y-$value in the given graph is $
-3
.$ Hence,
\begin{array}{l}\require{cancel}
f(2)=-3
.\end{array}
b) When $x=-1,$ the corresponding $y-$value in the given graph is $
2
.$ Hence,
\begin{array}{l}\require{cancel}
f(-1)=2
.\end{array}