换底公式

$$ \log_a b = \frac{\log_c b}{\log_c a} = \log_c b \cdot \log_a c $$

相关结论

$$ \because a^{\log_b n} = a^{\log_a n \log_b a} \\ \therefore a^{\log_b n} = n^{\log_b a} $$