A rational function is a function of the form $f(x) = \dfrac{p(x)}{q(x)}$, where
$p(x)$ and $q(x)$ are polynomials. The following video explores what
happens to the limit of a rational function $x \to \pm \infty$, depending on whether the degree of the numerator is more, equal, or less than the degree of the denominator.