Power Function on Strictly Positive Base is Continuous/Real Power

Theorem
Let $a \in \R_{>0}$.

Let $f : \R \to \R$ be the real-valued function defined as:
 * $f \left({ x }\right) = a^x$

where $a^x$ denotes $a$ to the power of $x$.

Then $f$ is continuous.

Proof
By definition, $a^x$ is the unique continuous extension of $a^r$, for rational $r$.

The result follows immediately.