Answer
Absolute maximum = $4$
No local maximum.
No absolute or local minimum.
Work Step by Step
The function is linear, its graph is a line. We need two points:
$f(1)=\frac{1}{2}[3(1)-1]=1$
$f(3)$ = $\frac{1}{2}[3(3)-1]$ = $4$
We graph the line.
Absolute maximum = $4$.
No local maximum.
No absolute or local minimum.