Part A:
The average rate of change refers to a function's slope. Thus, we are going to need to use the slope formula, which is:
![m = \dfrac{y_2 - y_1}{x_2 - x_1}](https://tex.z-dn.net/?f=m%20%3D%20%5Cdfrac%7By_2%20-%20y_1%7D%7Bx_2%20-%20x_1%7D)
and
are points on the function
You can see that we are given the x-values for our interval, but we are not given the y-values, which means that we will need to find them ourselves. Remember that the y-values of functions refers to the outputs of the function, so to find the y-values simply use your given x-value in the function and observe the result:
![h(0) = 3(5)^0 = 3 \cdot 1 = 3](https://tex.z-dn.net/?f=h%280%29%20%3D%203%285%29%5E0%20%3D%203%20%5Ccdot%201%20%3D%203)
![h(1) = 3(5)^1 = 3 \cdot 5 = 15](https://tex.z-dn.net/?f=h%281%29%20%3D%203%285%29%5E1%20%3D%203%20%5Ccdot%205%20%3D%2015)
![h(2) = 3(5)^2 = 3 \cdot 25 = 75](https://tex.z-dn.net/?f=h%282%29%20%3D%203%285%29%5E2%20%3D%203%20%5Ccdot%2025%20%3D%2075)
![h(3) = 3(5)^3 = 3 \cdot 125 = 375](https://tex.z-dn.net/?f=h%283%29%20%3D%203%285%29%5E3%20%3D%203%20%5Ccdot%20125%20%3D%20375)
Now, let's find the slopes for each of the sections of the function:
<u>Section A</u>
![m = \dfrac{15 - 3}{1 - 0} = \boxed{12}](https://tex.z-dn.net/?f=m%20%3D%20%5Cdfrac%7B15%20-%203%7D%7B1%20-%200%7D%20%3D%20%5Cboxed%7B12%7D)
<u>Section B</u>
![m = \dfrac{375 - 75}{3 - 2} = \boxed{300}](https://tex.z-dn.net/?f=m%20%3D%20%5Cdfrac%7B375%20-%2075%7D%7B3%20-%202%7D%20%3D%20%5Cboxed%7B300%7D)
Part B:
In this case, we can find how many times greater the rate of change in Section B is by dividing the slopes together.
![\dfrac{m_B}{m_A} = \dfrac{300}{12} = 25](https://tex.z-dn.net/?f=%5Cdfrac%7Bm_B%7D%7Bm_A%7D%20%3D%20%5Cdfrac%7B300%7D%7B12%7D%20%3D%2025)
It is 25 times greater. This is because
is an exponential growth function, which grows faster and faster as the x-values get higher and higher. This is unlike a linear function which grows or declines at a constant rate.