The function is .

Consider .

Find the inverse function.

Interchange the variables  and .

.

Substitute .

The inverse of the function is .

.

 is its own inverse function.

Graph :

Graph the function : .

Observe the graph:

The function is symmetrical about the line .

The inverse function is same as the function, therefore the graph of the function must be symmetrical about the line .

The graph is also symmetric over the horizontal asymptote .

.

Graph of :

The function is symmetrical about the line .

The graph of the function symmetrical about the line  and the graph is also symmetric over the horizontal asymptote .