Math Problem Statement

What is the average rate of change of the function f(x) = -3x + 5 over the interval x = -1 to x = 1?

Solution

The problem asks for the average rate of change of the function f(x)=3x+5f(x) = -3x + 5 over the interval x=1x = -1 to x=1x = 1.

The formula for the average rate of change of a function over an interval [a,b][a, b] is: Average rate of change=f(b)f(a)ba\text{Average rate of change} = \frac{f(b) - f(a)}{b - a}

Step-by-step solution:

  1. Identify the values:

    • a=1a = -1, b=1b = 1
    • Function: f(x)=3x+5f(x) = -3x + 5
  2. Compute f(a)f(a) and f(b)f(b):

    • f(1)=3(1)+5=3+5=8f(-1) = -3(-1) + 5 = 3 + 5 = 8
    • f(1)=3(1)+5=3+5=2f(1) = -3(1) + 5 = -3 + 5 = 2
  3. Substitute into the formula: Average rate of change=f(1)f(1)1(1)\text{Average rate of change} = \frac{f(1) - f(-1)}{1 - (-1)} =281+1= \frac{2 - 8}{1 + 1} =62=3= \frac{-6}{2} = -3

Final Answer:

The average rate of change of f(x)f(x) over the interval x=1x = -1 to x=1x = 1 is: 3\boxed{-3}

Let me know if you want a detailed explanation of any step!


Related Questions:

  1. What is the formula for the average rate of change, and why does it resemble the slope formula?
  2. How does the average rate of change of a linear function compare to its slope?
  3. What is the interpretation of a negative average rate of change in real-world terms?
  4. If the interval were x=2x = -2 to x=2x = 2, what would the average rate of change be for f(x)=3x+5f(x) = -3x + 5?
  5. How can you verify your result graphically?

Tip:

For linear functions like f(x)=3x+5f(x) = -3x + 5, the average rate of change over any interval is always equal to the slope of the line!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Average Rate of Change
Linear Functions

Formulas

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

Theorems

Slope of a Linear Function

Suitable Grade Level

Grades 8-10