Math Problem Statement

Is g(x) the inverse function of f(x)? Given: f(x) = (x + 2)^3 and g(x) = ³√x - 2.

Solution

To determine if g(x)g(x) is the inverse of f(x)f(x), we need to check if the compositions of these functions, f(g(x))f(g(x)) and g(f(x))g(f(x)), result in the identity function xx.

Step 1: Composition f(g(x))f(g(x))

Given:

  • f(x)=(x+2)3f(x) = (x + 2)^3
  • g(x)=x32g(x) = \sqrt[3]{x} - 2

Now, calculate f(g(x))f(g(x)): [ f(g(x)) = f\left(\sqrt[3]{x} - 2\right) = \left((\sqrt[3]{x} - 2) + 2\right)^3 = \left(\sqrt[3]{x}\right)^3 = x ] So, f(g(x))=xf(g(x)) = x.

Step 2: Composition g(f(x))g(f(x))

Next, calculate g(f(x))g(f(x)): g(f(x))=g((x+2)3)=(x+2)332=x+22=xg(f(x)) = g\left((x + 2)^3\right) = \sqrt[3]{(x + 2)^3} - 2 = x + 2 - 2 = x Thus, g(f(x))=xg(f(x)) = x.

Since both compositions f(g(x))=xf(g(x)) = x and g(f(x))=xg(f(x)) = x, we can conclude that g(x)g(x) is indeed the inverse of f(x)f(x).

So, the answer is "yes".

Would you like further explanation or have any questions?

Here are 5 related questions for deeper understanding:

  1. What is the general process to find the inverse of a function?
  2. How do you prove that two functions are inverses of each other?
  3. What are the domain and range of inverse functions?
  4. Can every function have an inverse? Why or why not?
  5. What are some real-world applications of inverse functions?

Tip: To confirm two functions are inverses, always check both compositions: f(g(x))=xf(g(x)) = x and g(f(x))=xg(f(x)) = x.

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Function Composition
Algebra

Formulas

f(g(x)) = x
g(f(x)) = x

Theorems

Inverse Function Theorem

Suitable Grade Level

Grades 10-12