Math Problem Statement

Allie has a piece of construction paper that she wants to use to make an open rectangular prism. She will cut a square with side length x from each corner of the paper, so the length and width is decreased by 2x as shown in the diagram. Write a function that models the volume of the rectangular prism.

Solution

To solve this problem, let’s analyze the information provided and derive the function for the volume of the rectangular prism.

Problem Breakdown

  1. Dimensions of the Paper: The piece of construction paper has an initial size of 1111 inches by 88 inches.
  2. Cutting Square Corners: Allie will cut squares of side length xx inches from each corner of the paper. After cutting these squares, she will fold the paper to form an open rectangular prism.
  3. Adjusted Dimensions:
    • The length of the paper after cutting the squares will be reduced by 2x2x, so the new length becomes 112x11 - 2x.
    • The width of the paper after cutting the squares will be reduced by 2x2x, so the new width becomes 82x8 - 2x.
    • The height of the box will be xx, since this is the height formed when the sides are folded up.

Volume Function

The volume VV of a rectangular prism is given by: V=length×width×heightV = \text{length} \times \text{width} \times \text{height}

Using the dimensions above:

  • Length = 112x11 - 2x
  • Width = 82x8 - 2x
  • Height = xx

Thus, the volume function f(x)f(x) is: f(x)=(112x)(82x)(x)f(x) = (11 - 2x)(8 - 2x)(x)

Simplification

Now, let’s simplify f(x)f(x):

  1. Expand (112x)(82x)(11 - 2x)(8 - 2x): = 88 - 38x + 4x^2$$
  2. Multiply this result by xx: = 4x^3 - 38x^2 + 88x$$

Final Answer

The function that models the volume of the rectangular prism is: f(x)=4x338x2+88xf(x) = 4x^3 - 38x^2 + 88x

Would you like further explanation on any of these steps, or assistance with other parts of the problem?


Here are five related questions to expand your understanding:

  1. What are the domain restrictions for the function f(x)f(x) in this context?
  2. How would you find the maximum volume of this rectangular prism?
  3. What happens to the volume as xx approaches the limits of the domain?
  4. How does changing the initial dimensions of the paper affect the volume function?
  5. Can we use calculus to find the value of xx that maximizes the volume?

Tip: Always verify the domain for variables in a geometric problem, as physical constraints limit possible values.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Volume of a Prism
Algebra
Polynomial Functions

Formulas

Volume of a rectangular prism V = length × width × height

Theorems

-

Suitable Grade Level

Grades 9-12