Question

If f(x) = x^2+2x+3, what is the average rate of change of f(x) over the interval [-4,6]

Answer 1

f(x) = x^2+2x+3
average rate of change is the slope of the line connecting (-4, f(-4)) to (6, f(6))
f(-4) = 16-8+3 = 11
f(6) = 36+12+3 = 51
(y2-y1)/(x2-x1) = (51-11)/(6--4) = 40/10 = 4 units