The equation of an exponential function can be written in the form
. The graph of an exponential function is either strictly increasing or strictly decreasing. The graph has a horizontal asymptote, which is a horizontal line that the curve approaches as
approaches infinity or negative infinity. All exponential functions can be graphed as transformations of the parent function
. A data set displayed in a scatterplot may approximate the shape of the graph of an exponential function. Technology can be used to generate an exponential function that best fits the data.