Math Problem Statement

For a function to have an inverse, it must be one-to-one. Which one of the following functions has an inverse?

Solution

In this question, there are two parts. Let's break them down:

Part (a): Conditions for Inverses

The question asks which function has an inverse. For a function to have an inverse, it must be one-to-one (bijective) rather than two-to-one.

  • g(x)=x3g(x) = x^3 is one-to-one since for every yy, there is a unique xx.
  • f(x)=x2f(x) = x^2 is not one-to-one (it fails the horizontal line test because for some yy, there are two xx values).

Thus, the correct choice for a function with an inverse is g(x)=x3g(x) = x^3. So, this should have been selected.

Part (b): Inverse of g(x)=x3g(x) = x^3

To find the inverse of g(x)=x3g(x) = x^3:

  1. Start with y=x3y = x^3.
  2. Solve for xx: x=y3x = \sqrt[3]{y}.
  3. Swap xx and yy to get the inverse: y=x3y = \sqrt[3]{x}.

So, the inverse of g(x)=x3g(x) = x^3 is g1(x)=x3g^{-1}(x) = \sqrt[3]{x}.

If part (b) was asking for the inverse of the chosen function, your input should be y=x1/3y = x^{-1/3} or y=x3y = \sqrt[3]{x} (which is the cube root of xx).

Corrections:

  • Part (a): You should choose g(x)=x3g(x) = x^3, since it has an inverse.
  • Part (b): The inverse function should be y=x3y = \sqrt[3]{x}.

Do you want more details or have any further questions?

Here are 5 related questions:

  1. Why can't f(x)=x2f(x) = x^2 have an inverse over the entire real line?
  2. What is the horizontal line test and how does it relate to inverses?
  3. Can f(x)=x2f(x) = x^2 have an inverse if restricted to x0x \geq 0?
  4. How do you find the inverse of more complex functions, like g(x)=x52g(x) = x^5 - 2?
  5. What is the geometric meaning of an inverse function?

Tip: When finding the inverse, always check if the function is one-to-one before proceeding with algebraic manipulation.

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Math Problem Analysis

Mathematical Concepts

Functions
Inverses
One-to-One Functions

Formulas

Inverse of a function: If y = f(x), then x = f^{-1}(y)

Theorems

Horizontal Line Test

Suitable Grade Level

Precalculus or College Level Mathematics