Answer
False.
Work Step by Step
A rational function is defined by $f(x)=\displaystyle \frac{p(x)}{q(x)}$,
where $p(x)$ and $q(x)$ are polynomial functions and $q(x)\neq 0$.
An exponential function with base a is defined as $f(x)=a^{x}$,
where $a>0$ and $a\neq 1$
$....................................$
For example, $f(x)=\displaystyle \frac{x}{x-1}$ is a rational function.
It, however, is not an exponential function
(can not be written in the form $f(x)=a^{x}$).
The statement is false.
