Math Problem Statement

Find the average rate of change for the function g(x) = 1 / (x + 3) over the interval [5, 5 + h], where h ≠ 0. Simplify your answer.

Solution

The problem asks to find the average rate of change of the function g(x)=1x+3g(x) = \frac{1}{x + 3} over the interval [5,5+h][5, 5 + h], where h0h \neq 0.

Step-by-Step Solution:

The average rate of change of a function g(x)g(x) over an interval [a,b][a, b] is given by the formula: Average Rate of Change=g(b)g(a)ba\text{Average Rate of Change} = \frac{g(b) - g(a)}{b - a} Here, a=5a = 5 and b=5+hb = 5 + h.

  1. Evaluate g(a)=g(5)g(a) = g(5): g(5)=15+3=18g(5) = \frac{1}{5 + 3} = \frac{1}{8}

  2. Evaluate g(b)=g(5+h)g(b) = g(5 + h): g(5+h)=1(5+h)+3=1h+8g(5 + h) = \frac{1}{(5 + h) + 3} = \frac{1}{h + 8}

  3. Substitute into the average rate of change formula: Average Rate of Change=1h+818(5+h)5\text{Average Rate of Change} = \frac{\frac{1}{h + 8} - \frac{1}{8}}{(5 + h) - 5} Simplify the denominator: (5+h)5=h(5 + h) - 5 = h So, the expression becomes: Average Rate of Change=1h+818h\text{Average Rate of Change} = \frac{\frac{1}{h + 8} - \frac{1}{8}}{h}

  4. Simplify the numerator: The difference of fractions in the numerator is: 1h+818=8(h+8)8(h+8)=8h88(h+8)=h8(h+8)\frac{1}{h + 8} - \frac{1}{8} = \frac{8 - (h + 8)}{8(h + 8)} = \frac{8 - h - 8}{8(h + 8)} = \frac{-h}{8(h + 8)}

  5. Substitute back into the expression: Average Rate of Change=h8(h+8)h\text{Average Rate of Change} = \frac{\frac{-h}{8(h + 8)}}{h} Simplify this by dividing by hh: Average Rate of Change=h8(h+8)×1h=18(h+8)\text{Average Rate of Change} = \frac{-h}{8(h + 8)} \times \frac{1}{h} = \frac{-1}{8(h + 8)}

Final Answer:

The average rate of change is: 18(h+8)\boxed{\frac{-1}{8(h + 8)}}

Would you like further clarification or a breakdown of any specific part?


Here are 5 related questions:

  1. How do you interpret the average rate of change geometrically?
  2. What is the derivative of g(x)=1x+3g(x) = \frac{1}{x+3}?
  3. How does the average rate of change compare to the instantaneous rate of change?
  4. What happens to the average rate of change as hh approaches 0?
  5. How would the formula change if the function had a different denominator, like g(x)=1x+5g(x) = \frac{1}{x + 5}?

Tip: The average rate of change formula is the same as the slope of the secant line connecting two points on the graph.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Average Rate of Change
Rational Functions
Algebra

Formulas

Average Rate of Change = (g(b) - g(a)) / (b - a)
g(x) = 1 / (x + 3)

Theorems

Basic Rate of Change Formula

Suitable Grade Level

High School (Grades 9-12)