Find the average rate of change for the function over the given interval.
-$y = x ^ { 2 } + 8 x$ between $x = 7$ and $x = 9$
A) $\frac { 16 } { 3 }$
B) 24
C) $\frac { 153 } { 2 }$
D) 17

Question

Quizplus · Accepted Answer

The average rate of change of a function $y = f(x)$ over an interval $[a, b]$ is given by $\frac{f(b) - f(a)}{b - a}$. For $y = x^2 + 8x$ between $x = 7$ and $x = 9$, we calculate $f(9) = 9^2 + 8(9) = 81 + 72 = 153$ and $f(7) = 7^2 + 8(7) = 49 + 56 = 105$. Thus, the average rate of change is $\frac{153 - 105}{9 - 7} = \frac{48}{2} = 24$.

Find the Average Rate of Change for the Function Over y=x2+8xy = x ^ { 2 } + 8 xy=x2+8x

Find the Average Rate of Change for the Function Over $y = x ^ { 2 } + 8 x$