Question

Which statement best describes the rate of change of the function below over the interval x < 4?

f(x) = x^2 - 8x + 19

a.negative and decreasing
b.negative and increasing
c.positive and increasing
d.positive and decreasing

Answer 1

df/ dx = 2 x -8

<0 for x< 4,

so f(x) decreases there.