Answer
$a.\quad\{x\in \mathbb{R}\ |\ -2\leq x\leq 4\}$
$b.\quad x=-1$
$c.\quad\{y\in \mathbb{R}\ |\ 1\leq y\leq 5\}$
Work Step by Step
The domain is the set of first coordinates of the points on the graph.
Here, domain $=\{x\in \mathbb{R}\ |\ $-2$\leq x\leq 4\}$
The range is the set of second coordinates of the points on the graph.
Here, range $=\{y\in \mathbb{R}\ |\ 1\leq y\leq 5\}$
The point $(-1,2)$ is on the graph, $f(-1)=2$
so $x=-1$ is the domain value for which $f(x)=2$
