Homogeneous system of linear equation:

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Homework Help Overview

The discussion revolves around solving a homogeneous system of linear equations involving three variables and two equations. Participants are exploring the implications of having fewer equations than unknowns and the nature of the solutions.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss how to approach the problem by selecting one variable as a parameter and expressing the others in terms of that parameter. There are questions about the validity of solving a system with more unknowns than equations and concerns about the multiple-choice answers provided.

Discussion Status

The discussion is ongoing, with participants offering various approaches to parameterizing the solution. Some guidance has been provided on how to set up the equations, but confusion remains regarding the multiple-choice answers and the overall process.

Contextual Notes

Participants are navigating the challenge of solving a system with three unknowns and only two equations, which raises questions about the nature of the solutions and the interpretation of the multiple-choice options given.

TonyC
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I am having trouble finding the solution to the homogeneous system of linear equations:
2x-2y+z=0
-2x+y+z=0
 
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I guess I should have also put:

How can I break this down?
 
Perhaps I have been out of the rigid math stuff for a while, but how are you going to solve a system with three unknowns and only two equations?
 
Choose one variable (e.g. z) as "t" and solve the system for x and y in function of t.
You'll get an infinite number of solutions, for every t (so z), you have a couple (x,y).
 
Hence my problem..
The answers to choose from are:
x=3/4t, y=-t,z=1/2t
x=-3/4t,y=-t,z=1/2t
z=-3/4t,y=t,z=1/2t
z=3/4t,y=t,z=1/2t

This is why I am stumped.
 
In your case, y was substituted for t. Then solve it as if t was a parameter for x and z.
 
? I am still confused.
 
You start with

[tex]\left\{ \begin{gathered}<br /> 2x - 2y + z = 0 \hfill \\<br /> - 2x + y + z = 0 \hfill \\ <br /> \end{gathered} \right[/tex]

Substitute y = t, t is now a parameter, and solve the following (2x2)-system for x and z

[tex]\left\{ \begin{gathered}<br /> 2x + z = 2t \hfill \\<br /> - 2x + z = - t \hfill \\ <br /> \end{gathered} \right[/tex]
 
You might also want to review your list of possible answers. "x" got changed to "z" in some of them!

(Am I the only person who hates multiple choice questions in mathematics?)
 
  • #10
HallsofIvy said:
(Am I the only person who hates multiple choice questions in mathematics?)
(No )
 

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