Math Problem Statement

solve

Find the average rate of change of \( f(x) = x^2 - 5x + 1 \) from \( x = 2 \) to \( x = 7 \).

Solution

To find the average rate of change of the function f(x)=x25x+1f(x) = x^2 - 5x + 1 from x=2x = 2 to x=7x = 7, we use the formula:

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

where a=2a = 2 and b=7b = 7.

Step 1: Evaluate f(2)f(2) and f(7)f(7)

  1. Calculate f(2)f(2): f(2)=(2)25(2)+1=410+1=5f(2) = (2)^2 - 5(2) + 1 = 4 - 10 + 1 = -5

  2. Calculate f(7)f(7): f(7)=(7)25(7)+1=4935+1=15f(7) = (7)^2 - 5(7) + 1 = 49 - 35 + 1 = 15

Step 2: Apply the Average Rate of Change Formula

Average Rate of Change=f(7)f(2)72=15(5)5=15+55=205=4\text{Average Rate of Change} = \frac{f(7) - f(2)}{7 - 2} = \frac{15 - (-5)}{5} = \frac{15 + 5}{5} = \frac{20}{5} = 4

Answer

The average rate of change of f(x)f(x) from x=2x = 2 to x=7x = 7 is 44.

Would you like more details on any step?


Here are 5 related questions to expand your understanding:

  1. How do you interpret the average rate of change of a function geometrically?
  2. What does a positive average rate of change indicate about the function?
  3. How would you find the average rate of change if the function were nonlinear, such as f(x)=x32x2+1f(x) = x^3 - 2x^2 + 1?
  4. How is the average rate of change different from the instantaneous rate of change?
  5. Can the average rate of change be zero? What would that imply?

Tip: The average rate of change of a function over an interval is equivalent to the slope of the secant line joining the endpoints of the interval on the graph.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Average Rate of Change

Formulas

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

Theorems

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Suitable Grade Level

Grades 9-11