Introduction: A function of the form $y(x)=a^x$, where $a$ ($a \neq 1)$ is a positive number, is called an exponential function with \em{base} $a$.
Theorem: We often use the following feature of an exponential function:
$a^x=a^y$ if and only if $x=y$.
Theorem: We often use the following feature of an exponential function:
$a^x=a^y$ if and only if $x=y$.