For which of the following functions is the average rate of change from x=−1 to x=2 equal to 5? Select TWO that apply.

Question

For which of the following functions is the average rate of change from x=−1 to x=2 equal to 5? Select TWO that apply.

A. f(x)=2x+5
B. f(x)=5x+1
C. f(x)=x^2+2x
D. f(x)=x^2+4x

Answer 1

B. f(x)=5x+1

D. f(x)=x^2+4x

The average rate of change for a function is found by subtracting the y-values at the two given x-values (in this case -1 and 2) and then dividing by the difference of the x-values. For functions B and D, the average rate of change from x=-1 to x=2 is 5. This can be verified by plugging in the values and calculating.