Math Problem Statement

Find the inverse function for each of the given functions: 7. f(x) = x + 3 8. f(x) = x + 5 9. f(x) = 2 - x 10. f(x) = 3 - x 11. f(x) = x / (x + 2) 12. f(x) = (2x + 3) / (5x + 4)

Solution

Let's solve the inverse of each function one by one.

7. f(x)=x+3f(x) = x + 3

To find f1(x)f^{-1}(x), follow these steps:

  1. Replace f(x)f(x) with yy: y=x+3y = x + 3
  2. Swap xx and yy: x=y+3x = y + 3
  3. Solve for yy: y=x3y = x - 3 Thus, the inverse function is: f1(x)=x3f^{-1}(x) = x - 3

8. f(x)=x+5f(x) = x + 5

  1. Start with y=x+5y = x + 5.
  2. Swap xx and yy: x=y+5x = y + 5
  3. Solve for yy: y=x5y = x - 5 Thus, the inverse function is: f1(x)=x5f^{-1}(x) = x - 5

9. f(x)=2xf(x) = 2 - x

  1. Start with y=2xy = 2 - x.
  2. Swap xx and yy: x=2yx = 2 - y
  3. Solve for yy: y=2xy = 2 - x Thus, the inverse function is: f1(x)=2xf^{-1}(x) = 2 - x

10. f(x)=3xf(x) = 3 - x

  1. Start with y=3xy = 3 - x.
  2. Swap xx and yy: x=3yx = 3 - y
  3. Solve for yy: y=3xy = 3 - x Thus, the inverse function is: f1(x)=3xf^{-1}(x) = 3 - x

11. f(x)=xx+2f(x) = \frac{x}{x+2}

  1. Let y=xx+2y = \frac{x}{x+2}.
  2. Multiply both sides by x+2x + 2: y(x+2)=xy(x + 2) = x
  3. Distribute yy: yx+2y=xyx + 2y = x
  4. Bring all terms involving xx on one side: yxx=2yyx - x = -2y Factor out xx: x(y1)=2yx(y - 1) = -2y
  5. Solve for xx: x=2yy1x = \frac{-2y}{y - 1} Thus, the inverse function is: f1(x)=2xx1f^{-1}(x) = \frac{-2x}{x - 1}

12. f(x)=2x+35x+4f(x) = \frac{2x+3}{5x+4}

  1. Let y=2x+35x+4y = \frac{2x+3}{5x+4}.
  2. Multiply both sides by 5x+45x + 4: y(5x+4)=2x+3y(5x + 4) = 2x + 3
  3. Distribute yy: 5yx+4y=2x+35yx + 4y = 2x + 3
  4. Bring all terms involving xx on one side: 5yx2x=34y5yx - 2x = 3 - 4y Factor out xx: x(5y2)=34yx(5y - 2) = 3 - 4y
  5. Solve for xx: x=34y5y2x = \frac{3 - 4y}{5y - 2} Thus, the inverse function is: f1(x)=34x5x2f^{-1}(x) = \frac{3 - 4x}{5x - 2}

If you have any questions or want further details, feel free to ask!

Here are some follow-up questions:

  1. How can you verify if two functions are inverses of each other?
  2. What is the graphical relationship between a function and its inverse?
  3. Can every function have an inverse? Why or why not?
  4. How does the horizontal line test relate to the invertibility of functions?
  5. How can you apply the concept of inverse functions in real-life scenarios?

Tip: A function has an inverse if it is one-to-one (bijective), meaning each input corresponds to exactly one output and vice versa.

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Algebra
Function Manipulation

Formulas

Inverse of a linear function: f(x) = x + c, f^-1(x) = x - c
Inverse of a rational function

Theorems

Inverses of one-to-one functions

Suitable Grade Level

High School (Grades 9-12)