In this question, we want to find the average rate of change of a function over an interval, it represents by how much f(x) changes when x changes by 1.
Average rate of change:
The average rate of change of a function over an interval [a,b] is given by:
[tex]A = \frac{f(b) - f(a)}{b - a}[/tex]
In this question:
[tex]f(x) = 2x^3 + 4[/tex]
Between x = 4 and x = 6, so [tex]a = 4, b = 6[/tex]. Then
[tex]f(a) = f(4) = 2*4^3 + 4 = 132[/tex]
[tex]f(b) = f(6) = 2*6^3 + 4 = 436[/tex]
Then
[tex]A = \frac{436 - 132}{6 - 4} = 152[/tex]
Thus, the average rate of change of the function is of 152, that is, when x changes by 1, y changes by 152.
For another problem involving an average rate of change, you can check https://brainly.com/question/14481908