Math Problem Statement

Given the function f left parenthesis x right parenthesis equals x cubed minus 3 ​, ​(a) Find f Superscript negative 1 Baseline left parenthesis x right parenthesis . ​(b) Graph f and f Superscript negative 1

in the same rectangular coordinate system. ​(c) Use interval notation to give the domain and the range of f and f Superscript negative 1 . Question content area bottom Part 1 ​(a) Find f Superscript negative 1 Baseline left parenthesis x right parenthesis . f Superscript negative 1 Baseline left parenthesis x right parenthesis equals nothing

Solution

Let's tackle the problem step-by-step.

(a) Finding the inverse of the function f(x)=x33f(x) = x^3 - 3:

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

  1. Start with y=f(x)=x33y = f(x) = x^3 - 3.
  2. Swap xx and yy to find the inverse: x=y33x = y^3 - 3
  3. Solve for yy: x+3=y3x + 3 = y^3 y=x+33y = \sqrt[3]{x + 3} Thus, the inverse function is: f1(x)=x+33f^{-1}(x) = \sqrt[3]{x + 3}

(b) Graphing f(x)f(x) and f1(x)f^{-1}(x):

The function f(x)=x33f(x) = x^3 - 3 is a cubic function, which has the characteristic shape of a cubic curve. The inverse function f1(x)=x+33f^{-1}(x) = \sqrt[3]{x + 3} is also a cubic-root function but reflects the inverse relationship.

I can describe the graph:

  • f(x)f(x) is increasing for all xx, with a point of inflection at x=0x = 0, where f(0)=3f(0) = -3.
  • f1(x)f^{-1}(x) is the reflection of f(x)f(x) across the line y=xy = x.

The graphs of f(x)f(x) and f1(x)f^{-1}(x) should intersect on this line y=xy = x. Both functions pass through the point (3,0)(-3, 0), and their behavior reflects each other symmetrically.

(c) Domain and Range of f(x)f(x) and f1(x)f^{-1}(x):

  • For f(x)=x33f(x) = x^3 - 3:

    • Domain: (,)(-\infty, \infty), because the cubic function is defined for all real numbers.
    • Range: (,)(-\infty, \infty), because cubic functions take all real values.
  • For f1(x)=x+33f^{-1}(x) = \sqrt[3]{x + 3}:

    • Domain: (,)(-\infty, \infty), since the cube root function is also defined for all real numbers.
    • Range: (,)(-\infty, \infty), because the cube root function also takes all real values.

Would you like a graph for further illustration? Let me know if you want additional details on any part!


Related questions:

  1. How do you find the inverse of more complex functions, such as quadratics?
  2. How does symmetry between a function and its inverse manifest graphically?
  3. What is the general method for finding the inverse of a function?
  4. How do different transformations affect the domain and range of a function?
  5. Can every function have an inverse?

Tip:

When finding the inverse of a function, always check that the function is one-to-one by using the horizontal line test. This ensures the inverse is a valid function.

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions and Inverses
Cubic Functions
Graphing

Formulas

Inverse function formula
Cubic function f(x) = x^3 - 3
Inverse f⁻¹(x) = ³√(x + 3)

Theorems

Inverse Function Theorem
Domain and Range Concepts

Suitable Grade Level

Grades 10-12