A constant function is a linear function whose graph has a slope of 0. In other words, as the values of x change, the function value y stays the same or constant. The equation of a constant function can always be written in the following form.

Here, b is the y-intercept. An example constant function is y=2.

Constant functions typically do not have x-intercepts. The only exception is the function y=0, which has an infinite number of x-intercepts.