The exponential function is one of the most
important functions in mathematics (though it
would have to admit that the linear function ranks
even higher in importance). ...
An exponential function can describe growth or
decay. ...
In the exponential growth of f(x), the
function doubles every time you add one to its
input x.
Exponential growth is a pattern of data that shows greater
increases with passing time, creating the curve of an exponential
function. For example, if a population of mice doubles every year
starting with two in the first year, the population would be four
in the second year, 16 in the third year, 256 in the fourth year,
and so on. The population is growing to the power of 2 each year in
this case (i.e., exponentially).