Change of base formula for logarithms

Learn how to rewrite any logarithmic expression in a different base. For example, rewrite log_2(3) as ln(3)/ln(2). This is very helpful for evaluating logarithms with a calculator, which only evaluates base-10 and base-e logarithms.

Evaluating logarithms: change of base rule

Evaluate logarithms: change of base rule

Using the logarithm change of base rule

Use the logarithm change of base rule

Proof of the logarithm change of base rule