THe population of Murrayville doubled in 30 years. What was the exponential growth rate?
An exponential function can always be written $\displaystyle y= Ae^{kx}$. The "exponential growth rate" is the constant, k.
The population when x= 0 is $\displaystyle Ae^0= A$. 30 years later, x= 30 and the population is 2A: $\displaystyle 2A= Ae^{30k}$ so [tex]e^{30k}= 2. Taking the logarithm of both sides 30k= ln(2) and k= ln(2)/30.
it's the formula q:
refer to:
Doubling time - Wikipedia, the free encyclopedia