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

$\log_2 a - 2\log_2 b$
Recall: $\log_a\left(\dfrac{M}{N}\right) = \log_a M-\log_a N$ Using the rule above gives; $\log_2 \left(\dfrac{a}{b^2} \right) = \log_2 a-\log_2 b^2$ Note that $\log_a M^r = r \log_a M$ Therefore, the expression above simplifies to: $\log_2 \left(\dfrac{a}{b^2} \right) = \boxed{\log_2 a - 2\log_2 b}$