Math Problem Statement

Perform the indicated operation on the following functions: Given f(x) and g(x), find operations like (f + g)(x), (fg)(x), (f/g)(x), and others.

Solution

Let's work through the problems one by one. Here's the breakdown of each problem with its solution:

1. Given f(x)=3x2+7xf(x) = 3x^2 + 7x and g(x)=2x2x1g(x) = 2x^2 - x - 1, find (f+g)(x)(f + g)(x)

We add the two functions: (f+g)(x)=f(x)+g(x)=(3x2+7x)+(2x2x1)(f + g)(x) = f(x) + g(x) = (3x^2 + 7x) + (2x^2 - x - 1) Simplify: (f+g)(x)=(3x2+2x2)+(7xx)1=5x2+6x1(f + g)(x) = (3x^2 + 2x^2) + (7x - x) - 1 = 5x^2 + 6x - 1 So, (f+g)(x)=5x2+6x1(f + g)(x) = 5x^2 + 6x - 1.


2. Given g(x)=6x+4g(x) = 6x + 4 and f(x)=2x7f(x) = 2x - 7, find (fg)(x)(fg)(x)

We multiply the two functions: (fg)(x)=f(x)g(x)=(2x7)(6x+4)(fg)(x) = f(x) \cdot g(x) = (2x - 7)(6x + 4) Use the distributive property: (fg)(x)=2x(6x+4)7(6x+4)=12x2+8x42x28(fg)(x) = 2x(6x + 4) - 7(6x + 4) = 12x^2 + 8x - 42x - 28 Simplify: (fg)(x)=12x234x28(fg)(x) = 12x^2 - 34x - 28 So, (fg)(x)=12x234x28(fg)(x) = 12x^2 - 34x - 28.


3. Given g(x)=6x+4g(x) = 6x + 4 and f(x)=2x7f(x) = 2x - 7, find g(x)f(x)g(x) - f(x)

Subtract the two functions: (gf)(x)=g(x)f(x)=(6x+4)(2x7)(g - f)(x) = g(x) - f(x) = (6x + 4) - (2x - 7) Distribute the negative sign: (gf)(x)=6x+42x+7=4x+11(g - f)(x) = 6x + 4 - 2x + 7 = 4x + 11 So, g(x)f(x)=4x+11g(x) - f(x) = 4x + 11.


4. Given f(x)=x22x+1f(x) = x^2 - 2x + 1 and g(x)=x1g(x) = x - 1, find (f/g)(x)(f/g)(x)

We divide the two functions: f(x)g(x)=x22x+1x1\frac{f(x)}{g(x)} = \frac{x^2 - 2x + 1}{x - 1} Factor the numerator: (x1)2x1\frac{(x - 1)^2}{x - 1} Cancel out the x1x - 1 terms: f(x)g(x)=x1\frac{f(x)}{g(x)} = x - 1 So, f(x)g(x)=x1\frac{f(x)}{g(x)} = x - 1 (for x1x \neq 1).


5. Given f(x)=x+4f(x) = x + 4 and g(x)=x4g(x) = x - 4, find (fg)(x)(fg)(x)

Multiply the two functions: (fg)(x)=f(x)g(x)=(x+4)(x4)(fg)(x) = f(x) \cdot g(x) = (x + 4)(x - 4) This is a difference of squares: (fg)(x)=x216(fg)(x) = x^2 - 16 So, (fg)(x)=x216(fg)(x) = x^2 - 16.


Let me know if you need more details on any of these steps or if you'd like me to continue with the remaining problems.

Questions:

  1. How would you factor quadratic expressions to simplify division?
  2. How can you identify when to use the difference of squares technique in multiplication?
  3. What are the common steps to multiply polynomials?
  4. When simplifying rational expressions, when should terms be canceled?
  5. How does the distributive property help in expanding polynomials?

Tip: Always check for factoring opportunities before simplifying polynomial divisions!

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Math Problem Analysis

Mathematical Concepts

Function Operations
Polynomial Addition
Polynomial Multiplication
Polynomial Division
Difference of Squares
Factoring

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

Polynomial Factorization
Difference of Squares Theorem

Suitable Grade Level

Grades 9-11