General Solution to System of Equations w/o Eigenvalues

Click For Summary
SUMMARY

The discussion focuses on solving a system of differential equations without relying on eigenvalues and eigenvectors. The equations presented are x' = 2x, y' = -x + 3y, and z' = 2x - 4y + 6z. A suggested method involves substituting the solution for x into the equation for y and subsequently solving for z, demonstrating a straightforward approach to finding the general solution. This method is particularly useful for lower triangular matrices, where the eigenvalues are 2, 3, and 6.

PREREQUISITES
  • Understanding of differential equations
  • Familiarity with systems of equations
  • Knowledge of matrix theory, specifically lower triangular matrices
  • Basic skills in substitution methods for solving equations
NEXT STEPS
  • Study the method of substitution in solving systems of differential equations
  • Learn about lower triangular matrices and their properties
  • Explore alternative methods for solving differential equations, such as Laplace transforms
  • Investigate the implications of eigenvalues and eigenvectors in systems of equations
USEFUL FOR

Students and educators in mathematics, particularly those studying differential equations and linear algebra, as well as anyone seeking to deepen their understanding of alternative solution methods for systems of equations.

hbomb
Messages
57
Reaction score
0
I have a question that involves a system of equations that I can't figure out

Give the general solution of the set of equations below:

x'=2x
y'=-x+3y
z'=2x-4y+6z

Hint: While you can use eigenvalues and eigenvectors for this one, there is an easier way to do it.

That's where I'm stuck, I know how to do this using the eigenvalues and eigenvectors.

This is a lower triangular matrix, so the eigenvalues are 2, 3, 6. But what's the other way of doing this?
 
Physics news on Phys.org
If x'=2x, what does x equal?

Plug that into the x for y' = -x + 3y, and solve for y.

Do the same for z then.

I find it a bit disconcerting that you have posted so many problems about these types of things, you may want to ask your professor to go over exactly what you're doing, since it looks like you just memorized the matrix formula and left it at that
 
Yea, he's very vague on some of these topics. He gives examples of finding determinants of matrices and finding eigenvalues and eigenvectors, but he never showed how to solve a system of equations with a given point.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
8
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
Replies
1
Views
1K
Replies
5
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
9
Views
2K