# Constant Function

A
**
constant function
**
is a
linear function
for which the
range
does not change no matter which member of the
domain
is used.
$f\left({x}_{1}\right)=f\left({x}_{2}\right)$
for any
${x}_{1}$
and
${x}_{2}$
in the domain.

With a constant function, for any two points in the interval, a change in $x$ results in a zero change in $f\left(x\right)$ .

**
Example:
**

Graph the function $f\left(x\right)=3$ .

The graph of a constant function is always a horizontal line .