An asymptote is a line that a curve approaches as it moves closer to infinity. Very commonly the asymptotes of a graph are the and axes.
There are three types of asymptotes: horizontal, vertical, and oblique. The x-axis is a horizontal asymptote, the y-axis is a vertical one, while oblique asymptotes are basically diagonal lines in a plane.
The distance between a curve and an asymptote approaches as they head towards infinity. The graph of a horizontal asymptote is given as , while the graph of a vertical asymptote is given as . Oblique asymptotes are given by the slope-intercept equation, .