Linear growth occur by adding the same amount in each unit of time. Exponential growth happens when an initial population increases by the same percentage or factor over equal time increments or generations.

Is growth rate linear or exponential?

Linear growth is always at the same rate, whereas exponential growth increases in speed over time. A linear function like f(x)=x has a derivative of f'(x)=1 , which means that it has a constant growth rate.

Are exponential models linear?

Linear models are used when a phenomenon is changing at a constant rate, and exponential models are used when a phenomenon is changing in a way that is quick at first, then more slowly, or slow at first and then more quickly.