The base of a logarithmic function

What are the key points on the graph of a logarithmic function?
Move the slider to change the base of the logarithmic function. [br]If the point [math]\left(a,1\right)[/math] is on the function [math]y=log_bx[/math], what is the value of [math]a[/math]?[br]This point is the first cycle point and it is a key point that can help us identify the base of a logarithm.

Information: The base of a logarithmic function