Average rate of change of a function
Initial explanation
We know that the average rate of change of a function between the point
x = a
and the point
x = b
is given by the formula:
This is how much the function changed on the y axis divided by the change in the x axis.
For this quadratic function...
In this case, we have that the points a and b are x = 2 and x = 4:
We can observe that
when x = 2
then f(2) = -3
when x = 4
then f(4) = -15
Then, using the formula, we have:
Answer: C. -6