To access it press alpha window and select the fifth option from the menu logBase. Therefore log 5 25 2. The difference of two logarithms of equal base.
Logarithms being special ways to make clear what exponent needed to multiply into a specific number.
To access it press alpha window and select the fifth option from the menu logBase. Log b x y log b x log b y Logarithm quotient rule. The number you immediately see is the exponent for the original number you entered. If you want to compute a logarithm with an arbitrary base but can access only a natural logarithm calculator or a log 10 base calculator you need to apply the following rules.