Question

Using complete sentences, explain how to find the average rate of change for f(x) from x = 4 to x = 7.

My equation is f(x)=4x↑2-48x+156

Thanks in advance

Answer 1

f(x)=4x\(^2\)-48x+156

substituting x for 4 gives
f(4) = 4(4)\(^2\)-48(4)+156 = 28

and for 7 gives
f(7) = 4(7)\(^2\)-48(7)+156 = 23

so between 7 and 4 there's a 23-28 = -5 difference

7 and 4 are 7-4=3 spaces apart, so the average rate of change is -5/3

Answer 2

Thank you so much- I understand it much better now. Thanks!