Math Problem Statement

Given the function f(x) = x^2 + 4x + 1, determine the average rate of change of the function over the interval -8 ≤ x ≤ 4.

Solution

The problem in the image asks for the average rate of change of the function f(x)=x2+4x+1f(x) = x^2 + 4x + 1 over the interval 8x4-8 \leq x \leq 4.

Solution:

The average rate of change of a function over an interval is given by the formula:

Average Rate of Change=f(b)f(a)ba\text{Average Rate of Change} = \frac{f(b) - f(a)}{b - a}

Where:

  • aa and bb are the endpoints of the interval (a=8,b=4a = -8, b = 4).
  • f(a)f(a) and f(b)f(b) are the values of the function at those points.
  1. Find f(a)f(a), where a=8a = -8: f(8)=(8)2+4(8)+1f(-8) = (-8)^2 + 4(-8) + 1 f(8)=6432+1=33f(-8) = 64 - 32 + 1 = 33

  2. Find f(b)f(b), where b=4b = 4: f(4)=(4)2+4(4)+1f(4) = (4)^2 + 4(4) + 1 f(4)=16+16+1=33f(4) = 16 + 16 + 1 = 33

  3. Substitute into the formula: Average Rate of Change=f(4)f(8)4(8)\text{Average Rate of Change} = \frac{f(4) - f(-8)}{4 - (-8)} Average Rate of Change=33334+8\text{Average Rate of Change} = \frac{33 - 33}{4 + 8} Average Rate of Change=012=0\text{Average Rate of Change} = \frac{0}{12} = 0

Final Answer:

0\boxed{0}

Would you like further clarification or details about this process?


Related Questions:

  1. What does the average rate of change tell us about the behavior of a function?
  2. How would the result change if the interval was different, for example 8x0-8 \leq x \leq 0?
  3. Can the average rate of change be negative? Why or why not?
  4. How does the formula for the average rate of change relate to the slope of a secant line?
  5. How would the average rate of change differ if the function were linear?

Tip:

When calculating the average rate of change, always simplify the interval difference first to avoid sign mistakes.

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Math Problem Analysis

Mathematical Concepts

Algebra
Average Rate of Change
Quadratic Functions

Formulas

Average Rate of Change = (f(b) - f(a)) / (b - a)

Theorems

Rate of Change Formula

Suitable Grade Level

Grades 9-11