Answer
$1$
Work Step by Step
From the graph we see that the value of $f(3)$ is approximately $2$.
From the graph we see that the value of $f(1)$ is approximately $0$.
$\frac{2-0}{3-1}=\frac{2}{2}=1$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.