Answer
3
Work Step by Step
The dashed line represents a horizontal asymptote at 3
(see section 2.3).
This means that as x moves toward the right
($ x\rightarrow+\infty$),
the function values get very close to
(but never reaches) 3.
Therefore, $\displaystyle \lim_{x\rightarrow\infty}f(x)=3$.