Return to Assignments Logarithmic functions and graphs
Assignment 6
Using their graphs show that the following functions (a logarithmic and an exponential function):
are inverse functions. Which line is the symmetry axis?
Solution
In the figure both functions are sketched based on a number of points. For the logarithmic function these points we take:
and for the exponential function:
We notice that the graph of one function can be obtained by the other by exchanging the variables 
and 
. Therefore the symmetry axis is the line: 
. We can see this in the figure above.
