Take a look at the applet: Exponential Functions
Every exponential function has a function rule that can be written as .
To obtain this form you may need to use the computation rules for powers.
You can obtain the graph of by using the following transformations on :
multiplication with respect to the -axis with ;
translation along the -axis with units.
Therefore the graph determined by has a horizontal asymptote: the line .
You find the potential zero by solving . This often requires a calculator.