Answer
the limit does not exist,
$\displaystyle \lim_{x\rightarrow-\infty}f(x)= +\infty$
Work Step by Step
Follow the steps in "Evaluating Limits Graphically"
(step 6: evaluating $\displaystyle \lim_{x\rightarrow-\infty}$f(x))
As we trace the graph to the far left ,
f(x) increases without bound, does not approach any particular value.
When f(x) is becoming arbitrarily large as x$\rightarrow$a,
we also say that $\displaystyle \lim_{x\rightarrow a}$f(x) diverges to +$\infty$, or just $\displaystyle \lim_{\mathrm{x}\rightarrow a}f(x)$=+$\infty$.
The limit diverges to +$\infty,$
meaning that
the limit does not exist, and
$\displaystyle \lim_{x\rightarrow-\infty}f(x)= +\infty$
