Sketch the graph of the given function, evaluate the given expressions, and then use technology to duplicate the graphs. Give the technology formula.
Sketch the graph of the given function, evaluate the given expressions, and then use technology to duplicate the graphs. Give the technology formula.
$f(x)=\left\{\begin{array}{ll}-1 & \text { if }-4 \leq x \leq 0 \\ x & \text { if } 0<x \leq 4\end{array}\right.$
a. $f(-1)$
b. $f(0)$
c. $f(1)$