What is the value of log base a of 1, for any allowed base a?

1. A logarithm answers the question of what exponent the base needs. 2. Any allowed base raised to the power 0 gives 1. 3. So the exponent needed to reach 1 is 0, which makes log base a of 1 equal to 0. _Source: OpenStax Intermediate Algebra (CC BY 4.0), section 10.4 Use the Properties of Logarithms_