## Calculus with Applications (10th Edition)

y = $-4x^{2}$ - 6 between x = 2 and x = 6 To find the rate of change, you have to use the rate of change formula: $\frac{f(b)-f(a)}{b-a}$ In this problem, the starting point is at 2 and the end point is 6. Therefore, a = 2 and b = 6. Knowing this, you can plug these numbers back into the formula. $\frac{(-4\times 6^{2}-6) - (-4\times 2^{2}-6)}{6-2}$ = $\frac{(-4\times 36-6) - (-4\times 4-6)}{4}$ = $\frac{-150 - (-22)}{4}$ = $\frac{-128}{4}$ = -32 Therefore, the rate of change equals -32.