homework assignment 3.3 rates of change and behavior of graphs score: 3/11 answered: 3/11 question 5 find…

homework assignment 3.3 rates of change and behavior of graphs score: 3/11 answered: 3/11 question 5 find the average rate of change of f(x)=4x^2 - 5 on the interval 1,b. your answer will be an expression involving b. question help: video written example message instructor submit question
Answer
Explanation:
Step1: Recall average rate - of - change formula
The average rate of change of a function $y = f(x)$ on the interval $[a,b]$ is $\frac{f(b)-f(a)}{b - a}$. Here, $a = 1$ and $f(x)=4x^{2}-5$.
Step2: Find $f(1)$ and $f(b)$
First, find $f(1)$: Substitute $x = 1$ into $f(x)=4x^{2}-5$, we get $f(1)=4\times1^{2}-5=4 - 5=-1$. Then, find $f(b)$: Substitute $x = b$ into $f(x)=4x^{2}-5$, we get $f(b)=4b^{2}-5$.
Step3: Calculate the average rate of change
Using the formula $\frac{f(b)-f(1)}{b - 1}$, substitute $f(1)=-1$ and $f(b)=4b^{2}-5$: [ \begin{align*} \frac{f(b)-f(1)}{b - 1}&=\frac{(4b^{2}-5)-(-1)}{b - 1}\ &=\frac{4b^{2}-5 + 1}{b - 1}\ &=\frac{4b^{2}-4}{b - 1}\ &=\frac{4(b^{2}-1)}{b - 1}\ &=\frac{4(b - 1)(b + 1)}{b - 1}\ &=4(b + 1) \end{align*} ]
Answer:
$4(b + 1)$