# How do you find vertical asymptotes using limits?

The vertical line $x = a$ is a vertical asymptote of $f(x)$ if either
${\lim}_{x \to {a}^{-}} f \left(x\right) = \pm \infty$ or ${\lim}_{x \to {a}^{+}} f \left(x\right) = \pm \infty$.
So, we need to find $a$-values such that either the left-hand limit or the right-hand limit is $\pm \infty$.