Math Problem Statement

Find the inverse of the following functions: f(x) = 3x - 7, g(x) = 9 - 2x, h(x) = (1/4)x + 5, k(x) = 2 - (1/5)x

Solution

The question asks for the inverse functions of the given functions. Let's solve them one by one:

  1. f(x) = 3x - 7

    • To find the inverse, swap xx and yy in the equation: y=3x7y = 3x - 7 Swap xx and yy: x=3y7x = 3y - 7 Solve for yy: x+7=3y    y=x+73x + 7 = 3y \implies y = \frac{x + 7}{3} Therefore, the inverse function is: f1(x)=x+73f^{-1}(x) = \frac{x + 7}{3}
  2. g(x) = 9 - 2x

    • Start by swapping xx and yy: y=92xy = 9 - 2x Swap xx and yy: x=92yx = 9 - 2y Solve for yy: 2y=9x    y=9x22y = 9 - x \implies y = \frac{9 - x}{2} Therefore, the inverse function is: g1(x)=9x2g^{-1}(x) = \frac{9 - x}{2}
  3. h(x) = \frac{1}{4}x + 5

    • Swap xx and yy: y=14x+5y = \frac{1}{4}x + 5 Swap xx and yy: x=14y+5x = \frac{1}{4}y + 5 Solve for yy: x5=14y    y=4(x5)x - 5 = \frac{1}{4}y \implies y = 4(x - 5) Therefore, the inverse function is: h1(x)=4(x5)h^{-1}(x) = 4(x - 5)
  4. k(x) = 2 - \frac{1}{5}x

    • Swap xx and yy: y=215xy = 2 - \frac{1}{5}x Swap xx and yy: x=215yx = 2 - \frac{1}{5}y Solve for yy: 15y=2x    y=5(2x)\frac{1}{5}y = 2 - x \implies y = 5(2 - x) Therefore, the inverse function is: k1(x)=5(2x)k^{-1}(x) = 5(2 - x)

Do you want more details, or do you have any questions?

Here are five related questions for you to consider:

  1. How can you verify if a function is one-to-one before finding its inverse?
  2. What is the graphical relationship between a function and its inverse?
  3. Can all functions have an inverse? If not, why?
  4. How can you use the horizontal line test to check if a function has an inverse?
  5. What happens to the domain and range of a function when you find its inverse?

Tip: To check if your inverse function is correct, compose the original and inverse functions. The result should be xx.

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Algebra
Linear Functions

Formulas

To find the inverse of a function f(x), swap x and y in the equation y = f(x), then solve for y.

Theorems

Inverse Function Theorem

Suitable Grade Level

Grades 10-12