Math Problem Statement

Find the following: (f + g)(x), (f - g)(x), (fg)(x), f/g(x), and determine the domain of f/g(x). Given f(x) = x + 8 and g(x) = x - 8.

Solution

It looks like you are working on a math problem related to functions and their domains, involving operations like addition, subtraction, multiplication, and division of functions.

From the image, we have the following information:

  1. f(x)=x+8f(x) = x + 8
  2. g(x)=x8g(x) = x - 8

You are asked to find the following:

  • (f+g)(x)(f + g)(x)
  • (fg)(x)(f - g)(x)
  • (fg)(x)(fg)(x)
  • fg(x)\frac{f}{g}(x)
  • The domain of fg(x)\frac{f}{g}(x)

Let’s go step by step.

(a) (f+g)(x)(f + g)(x)

(f+g)(x)=f(x)+g(x)=(x+8)+(x8)=2x(f + g)(x) = f(x) + g(x) = (x + 8) + (x - 8) = 2x

(b) (fg)(x)(f - g)(x)

(fg)(x)=f(x)g(x)=(x+8)(x8)=x+8x+8=16(f - g)(x) = f(x) - g(x) = (x + 8) - (x - 8) = x + 8 - x + 8 = 16

(c) (fg)(x)(fg)(x)

(fg)(x)=f(x)g(x)=(x+8)(x8)=x264(fg)(x) = f(x) \cdot g(x) = (x + 8)(x - 8) = x^2 - 64

(d) fg(x)\frac{f}{g}(x)

fg(x)=x+8x8\frac{f}{g}(x) = \frac{x + 8}{x - 8}

Domain of fg(x)\frac{f}{g}(x)

The domain of fg(x)\frac{f}{g}(x) is all real numbers except where the denominator is zero. So we need to find where g(x)=x8=0g(x) = x - 8 = 0.

Solving x8=0x - 8 = 0, we get x=8x = 8.

Thus, the domain of fg(x)\frac{f}{g}(x) is all real numbers except x=8x = 8. In interval notation, the domain is: (,8)(8,)(-\infty, 8) \cup (8, \infty)

Summary of Answers:

  • (a) (f+g)(x)=2x(f + g)(x) = 2x
  • (b) (fg)(x)=16(f - g)(x) = 16
  • (c) (fg)(x)=x264(fg)(x) = x^2 - 64
  • (d) fg(x)=x+8x8\frac{f}{g}(x) = \frac{x + 8}{x - 8}
  • Domain of fg(x)\frac{f}{g}(x): (,8)(8,)(-\infty, 8) \cup (8, \infty)

Would you like more details or explanations on any step? Here are some follow-up questions for deeper exploration:

  1. How can you verify the domain of a function involving division?
  2. What happens to the domain if a function includes a square root or logarithm?
  3. Can you describe how multiplication of functions affects their domain?
  4. How would you solve a problem if f(x)f(x) and g(x)g(x) involved more complex expressions?
  5. What are the key differences between operations on functions and operations on real numbers?

Tip: Always check for restrictions in the domain, particularly when dealing with division or square roots in functions.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Functions
Addition of Functions
Subtraction of Functions
Multiplication of Functions
Division of Functions
Domain of Functions

Formulas

(f + g)(x) = f(x) + g(x)
(f - g)(x) = f(x) - g(x)
(fg)(x) = f(x) * g(x)
(f/g)(x) = f(x) / g(x)

Theorems

Domain of Rational Functions: For f/g(x), g(x) ≠ 0.

Suitable Grade Level

Grades 10-12