Answer:
the average rate of change of f(x) over the interval [6, 8] is, 0
Explanation:
Average rate of change (A(x)) of f(x) over interval [a, b] is given by:
....[1]
As per the statement:
Given the function:

At x = 6

⇒

At x = 8

⇒

We have to find the average rate of change of f(x) over the interval [6, 8]
Substitute the given values in [1] we have;
Therefore, the average rate of change of f(x) over the interval [6, 8] is, 0