Answer
Explanation given below.
Work Step by Step
As x approaches the value a from the either side,
we observe the y coordinate on the graph of f, which is f(x).
The closer x gets to a (but not a itself),
f(x) becomes a greater and greater positive number .
(the graph rises without bound when x approaches a from either side)
The limit at a does not exist, but with the annotation $\displaystyle \lim_{x\rightarrow a}f(x)=\infty,$
we emphasize that both sides of the graph go upward without bound when x is close to a.
Had one side gone up, and the other down without bound, we would have stated that the limit does not exist.
