Answer
To find a function value $f(a)$ from the graph of $f$, we find
the height of the graph above the x-axis at $x=\fbox{a}.$
From the graph of f we see that $f(3)=\fbox{4}$ and $f(1)=\fbox{0} .$
The net change in f between $x=1$ and $x=3$
is $f(\fbox{3})-f(\fbox{1})=4-1=\fbox{4}$
(fill in the blanks)
Work Step by Step
The exercise is to fill in the blanks - no special steps.
