How many wil there be after 8 years?
When will we reach 3500 inhabitants?

A city has 2804 inhabitants. 
Five years later there are 2973 inhabitants.
We assume an exponential growth. 
Describe this as a function.

Let f(x) be an exponential function with starting value 
200 and a growth of 13% each year. 
Make the formula for the function.

How many years will it take to double the y-value? 