AP Precalculus / Unit 2: Exponential and Logarithmic Functions
2.9 Logarithmic Expressions
Notes
$\log_b a=c$ means $b^c=a$. A log is an exponent.
- $\log_b 1=0$; $\log_b b=1$.
- $\ln$ is $\log_e$; $\log$ alone means $\log_{10}$.
Practice
$\log_2 32=$
$2^5=32$.
$\log_{10}0.01=$
$10^{-2}=0.01$.
$\ln e^4=$
$\ln$ undoes $e$.
Ready for more? Take the Unit 2 test.