Question

For the quadratic function below, what is the rate of change over the interval.

5 ≤ x ≤ 6

--
2
1
-2
-1

Answer 1

Explanation:

Intervals are always x values. When x = 5, y = 4 (look at the graph to se this); when x = 6, y = 2. The rate of change is the same thing as the slope. We can't get an exact slope here because this isn't a straight line, but we can find the average rate of change. We use the slope formula to do this: with the coordinates (5, 4) and (6, 2):

`m=(2-4)/(6-5)=(-2)/(1)=-2`. Third choice down is the one you want.