# What is an exponential function?

##### 2 Answers

The exponential function is used to model a relationship in which a constant change in the independent variable gives the same proportional change in the dependent variable.

The function is often written as **exp(x)** It is widely used in physics, chemistry, engineering, mathematical biology, economics and mathematics.

An exponential function is a function of the form

For integer and rational

For irrational

Examples:

The last example illustrates why we also consider

We can write