## Calculus 10th Edition

An asymptote is a special line that tells us something about the behaviour of a function as it approaches a value: 1) A vertical asymptote of equation $x=c$ represents a function approaching $+\infty$ and/or $-\infty$ as $x$ approaches $c$. 2) A horizontal asymptote of equation $y=d$ tells us that as a $x$ approaches $+\infty$ and/or $-\infty,$ $f(x)$ approaches $d.$