Math Problem Statement

Question content area top Part 1 Given ​f(x)equals7 plus StartFraction 1 Over x EndFraction and ​g(x)equalsStartFraction 1 Over x EndFraction find fplus​g, fminus​g, ​fg, and StartFraction f Over g EndFraction . Determine the domain for each function. Question content area bottom Part 1 ​(fplus​g)(x)equals    7 plus StartFraction 2 Over x EndFraction ​(Simplify your​ answer.) Part 2 What is the domain of f plus g​? Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice. A. The domain of fplusg is StartSet nothing EndSet    . ​(Use a comma to separate answers as​ needed.) B. The domain of fplusg is    left parenthesis negative infinity comma 0 right parenthesis union left parenthesis 0 comma infinity right parenthesis. ​(Type your answer in interval​ notation.) Your answer is correct.C. The domain of fplusg is empty set. Part 3 ​(fminus​g)(x)equals    7 ​(Simplify your​ answer.) Part 4 What is the domain of f minus g​? Select the correct choice below​ and, if​ necessary, fill in the answer box to complete your choice. A. The domain of fminusg is StartSet nothing EndSet    . ​(Use a comma to separate answers as​ needed.) B. The domain of fminusg is    left parenthesis negative infinity comma 0 right parenthesis union left parenthesis 0 comma infinity right parenthesis. ​(Type your answer in interval​ notation.) Your answer is correct.C. The domain of fminusg is empty set. Part 5 ​(fg)(x)equals    enter your response here ​(Simplify your​ answer.)

Solution

Let's break this problem down step by step. We're given two functions:

  1. f(x)=7+1xf(x) = 7 + \frac{1}{x}
  2. g(x)=1xg(x) = \frac{1}{x}

We need to find:

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

Part 1: Find (f+g)(x)(f + g)(x)

We can add the functions directly:

= \left( 7 + \frac{1}{x} \right) + \frac{1}{x} = 7 + \frac{2}{x}$$ So, $$(f + g)(x) = 7 + \frac{2}{x}$$. ### Part 2: Domain of $$(f + g)(x)$$ Both functions $$f(x)$$ and $$g(x)$$ involve division by $$x$$, so the domain will exclude $$x = 0$$. Hence, the domain of $$(f + g)(x)$$ is: $$(-\infty, 0) \cup (0, \infty)$$ ### Part 3: Find $$(f - g)(x)$$ Now, subtract the functions: $$(f - g)(x) = f(x) - g(x) = \left( 7 + \frac{1}{x} \right) - \frac{1}{x} = 7$$ So, $$(f - g)(x) = 7$$. ### Part 4: Domain of $$(f - g)(x)$$ Since $$(f - g)(x) = 7$$ is a constant and does not involve $$x$$, its domain is the same as the domain of the original functions, which is: $$(-\infty, 0) \cup (0, \infty)$$ ### Part 5: Find $$(fg)(x)$$ Now, multiply the functions: $$(fg)(x) = f(x) \cdot g(x) = \left( 7 + \frac{1}{x} \right) \cdot \frac{1}{x} = \frac{7}{x} + \frac{1}{x^2}$$ So, $$(fg)(x) = \frac{7}{x} + \frac{1}{x^2}$$. ### Part 6: Find $$\frac{f}{g}(x)$$ Finally, divide the functions: $$\frac{f}{g}(x) = \frac{f(x)}{g(x)} = \frac{7 + \frac{1}{x}}{\frac{1}{x}} = \left(7 + \frac{1}{x}\right) \cdot x = 7x + 1$$ So, $$\frac{f}{g}(x) = 7x + 1$$. ### Summary: 1. $$(f + g)(x) = 7 + \frac{2}{x}$$ 2. Domain of $$(f + g)(x)$$ is $$(-\infty, 0) \cup (0, \infty)$$ 3. $$(f - g)(x) = 7$$ 4. Domain of $$(f - g)(x)$$ is $$(-\infty, 0) \cup (0, \infty)$$ 5. $$(fg)(x) = \frac{7}{x} + \frac{1}{x^2}$$ 6. $$\frac{f}{g}(x) = 7x + 1$$ Would you like further explanation on any of these steps or the domains? --- Here are some related questions for practice: 1. How would you find the domain of the function $$f(x) = \frac{1}{x - 3}$$? 2. What happens to the domain of $$f(x) = \frac{1}{x - 3}$$ if we multiply by $$g(x) = x + 2$$? 3. Can you find the domain of $$\frac{1}{x^2 - 9}$$? 4. What is the inverse of $$f(x) = 7 + \frac{1}{x}$$? 5. How do you handle limits involving functions with denominators like these? **Tip:** Always pay close attention to points where division by zero might occur, as these will affect the domain of the function.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Functions
Domain of functions
Addition and subtraction of functions
Multiplication and division of functions

Formulas

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

Theorems

Domain of a rational function
Domain restrictions due to division by zero

Suitable Grade Level

Grades 9-11