Note:
If fx(x) changes from f(x₁) to f(x₂), the rate of change is
Rate = [f(x₂) - f(x₁)]/(x₂ - x₁)
From the table, we can compute rates of change as follows:
Change in x Change in f(x) Change in x Rate
----------------- -------------------- ----------------- ---------
[-4,-2] 0 - (-12) = 12 0 - (-2) = 2 6
[-2, 1] 3 - 0 = 3 1 - (-2) = 3 1
[-3, 1] 3 - (-5) = 8 1 - (-3) = 4 2
[-4, 0] 4 - (-12) = 16 0 - (-4) = 4 4
