find the average rate of the function over the given interval

y = x ^ 2 + 4x, [3, 8]

1 answer

To find the average rate of the function over the interval [3, 8], we need to calculate the average rate of change, also known as the slope of the line connecting the endpoints.

The formula for the average rate of change is given by:

Average Rate of Change = (f(b) - f(a)) / (b - a)

Where f(b) represents the value of the function at the endpoint b, f(a) represents the value of the function at the endpoint a, and b and a are the endpoints of the interval.

In this case, the endpoints are a = 3 and b = 8.

Let's calculate the average rate of change:

f(3) = (3^2) + 4(3) = 9 + 12 = 21
f(8) = (8^2) + 4(8) = 64 + 32 = 96

Average Rate of Change = (f(8) - f(3)) / (8 - 3)
= (96 - 21) / (8 - 3)
= 75 / 5
= 15

Therefore, the average rate of the function over the interval [3, 8] is 15.