## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$3$
$\because y=\log_a x \text{ is equivalent to } x= a^y$ $\therefore x = \log_4 64 \text{ is equivalent to } 64=4^x$ Solve the equation above using the rule $a^m=a^n\implies m=n$ to obtain: \begin{align*} 64&=4^x\\\\ 4^3&=4^x\\\\ 3&=x\end{align*}