Straightforward Multivariable Calculus Max/Min Problem

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SUMMARY

The discussion focuses on optimizing the area of shapes formed from a 20-inch piece of wire, which is to be divided into three parts: a square, a rectangle with length twice its width, and an equilateral triangle. The area equations provided are A=L^2 for the square, A=1/2 L^2 for the rectangle, and A=√(3/4) L^2 for the triangle. A critical point raised is the need to differentiate the variable 'L' for each shape to avoid confusion in calculations. The goal is to maximize the total area of these shapes.

PREREQUISITES
  • Understanding of multivariable calculus concepts, particularly optimization.
  • Familiarity with area formulas for geometric shapes: squares, rectangles, and equilateral triangles.
  • Basic algebra skills for manipulating equations and solving for variables.
  • Knowledge of constraints in optimization problems.
NEXT STEPS
  • Study optimization techniques in multivariable calculus, focusing on Lagrange multipliers.
  • Learn how to differentiate between variables in mathematical problems to avoid confusion.
  • Explore geometric properties and area calculations for various shapes.
  • Practice solving similar optimization problems involving constraints and multiple variables.
USEFUL FOR

Students studying calculus, particularly those tackling optimization problems, as well as educators looking for examples of practical applications of multivariable calculus concepts.

CRBK92
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Homework Statement


A 20-inch piece of wire is to be cut into three pieces. From one piece is made a square and from another is made a rectangle with length equal to twice its width. From the third is made an equilateral triangle. How should the wire be cut so that the sum of the three areas is a maximum?

Homework Equations



Square: A=L^2
Rectangle: A=1/2 L^2
Equilateral Triangle: A=√(3/4) L^2

The Attempt at a Solution


Where do I begin?
 
Last edited:
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CRBK92 said:

Homework Statement


A 20-inch piece of wire is to be cut into three pieces. From one piece is made a square and from another is made a rectangle with length equal to twice its width. From the third is made an equilateral triangle. How should the wire be cut so that the sum of the three areas is a maximum?

Homework Equations



Square: A=L^2
Rectangle: A=1/2 L^2
Equilateral Triangle: A=√(3/4) L^2


The Attempt at a Solution


Where do I begin?

You might begin by not using the same letter L to represent three different things.
 

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