# Logarithms and Logarithmic Functions

To begin our study of logarithmic functions, we're introduced to the basics of logarithms. For example, the logarithm definition tells us that to switch 'log base 9 of 81 equals 2' from logarithmic form to exponential form, the base of the logarithm is the base of the power, the number on the other side of the equation is the exponent, and the number inside the logarithm is the result. So we have 9^2 = 81. Going in the other direction, the logarithm definition tells us that to switch 6^0 = 1 from exponential form to logarithmic form, the base of the power is the base of the log, the exponent goes on the other side of the equation, and the result goes inside the log. So we have 'log base 6 of 1 equals 0.' The logarithm definition is used throughout the chapter on logarithmic functions. No logarithm calculator is required.