Math Problem Statement

Brody wants to write the inverse function of y = 3x - 8. Which of the following is mathematically equivalent to the inverse function?

Solution

We are tasked with finding the inverse of the function y=3x8y = 3x - 8 and determining which of the options (A, B, C, or D) is equivalent to this inverse.

Steps to find the inverse:

  1. Start with the equation: y=3x8y = 3x - 8
  2. Swap xx and yy (this is the process for finding the inverse function): x=3y8x = 3y - 8
  3. Solve for yy: x+8=3yx + 8 = 3y y=x+83y = \frac{x + 8}{3} This is the inverse function.

Now, let's examine the choices:

  • A: y=13x8y = \frac{1}{3x - 8} — This is not equivalent to the inverse function.
  • B: y=3x8y = \frac{3}{x} - 8 — Also not equivalent.
  • C: y=3x+8-y = -3x + 8 — Simplifying this: y=3x8y = 3x - 8, which is just the original function, not the inverse.
  • D: x=3y8x = 3y - 8 — This matches the equation we had right before solving for yy, so this is equivalent to the inverse.

Correct Answer: D

Would you like further clarification or more details on this problem?

Here are some related questions:

  1. How do you verify an inverse function?
  2. What is the significance of swapping xx and yy when finding an inverse?
  3. Can a function always have an inverse?
  4. How do horizontal line tests relate to inverse functions?
  5. How do you graph the inverse of a function?

Tip: To check if two functions are inverses, you can compose them: if f(f1(x))=xf(f^{-1}(x)) = x and f1(f(x))=xf^{-1}(f(x)) = x, then they are inverses.

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Math Problem Analysis

Mathematical Concepts

Inverse functions
Linear equations

Formulas

y = (x + 8)/3

Theorems

Inverse function theorem

Suitable Grade Level

Grades 9-12