Understanding Eigen Vectors and Diagonalization for a 2x2 Matrix

In summary, the conversation discusses finding eigenvalues and eigenvectors for a 2x2 matrix. The eigenvalues are calculated to be 30.77 and 9.22, but there is confusion about how to proceed with finding the eigenvectors. The process for finding eigenvectors is explained, and it is suggested to use 9.23 as an eigenvalue instead of rounding it. The equations given for finding the eigenvectors are found to be the same, and the need for normalization is mentioned. The conversation then moves on to discussing diagonalizing the matrix and sketching the unit standard deviation contour.
  • #1
koolrizi
21
0
I am trying to find eigen values and eigen vectors for A
Its 2X2 matrix. A first row (16 -10) second row (-10 24)
I got Eigen values as 30.77 and 9.22 but when i try to find eigen vectors here are the equations I end up with
-14.77v1 - 10v2= 0
-10v1 - 6.77v2 = 0

Kinda confused how to proceed with this.

Thanks
 
Physics news on Phys.org
  • #2
Use 9.23, you rounded wrong.

The procedure for finding associated eigenvectors is to find the nullspace of A-λI. So you have to solve the nullspace of that matrix you wrote up to find the 30.77-eigenspace. Then you'll need to do the process again for 9.23.

Does this clear things up for you? Or do you need help with solving the nullspace? Because that should be easy.
 
  • #3
these two equations are not compatible, because you have rounded your eigenvalues, but if you would have used the ratios as an eigenvalued, you'd see that these thwo equations are exactly the same.

When you are solveing for eigenvectors you have to use either of these equation, because they are same, and then if your states are normalizabe, you have to normalize it.

v1^2+v2^2=1

that's your second equation in system!
 
  • #4
(You should use fractions instead of decimals)

You've spent the whole semester solving problems like that, haven't you? So what's the trouble?
 
  • #5
Got it

Thanks I got that part. I didnt realize that v1=-0.677v2 for both equations. I am actually taking a different course which uses linear algebra but its been a while since i studied it. Now I have to diagonalize the matrix and also sketch the unit standard deviation contour. If you know any good sites for that do let me know.

Thanks everyone
 

1. What are eigen vectors?

Eigen vectors are special vectors that represent the directions along which a linear transformation has a simple effect, such as a scaling or rotation. They are also known as characteristic vectors.

2. How do you find eigen vectors?

To find eigen vectors, you first need to find the eigenvalues of a matrix. Then, for each eigenvalue, you need to solve the equation (A - λI)v = 0, where A is the matrix, λ is the eigenvalue, and v is the eigen vector. This will give you a set of eigen vectors for each eigenvalue.

3. What is the importance of eigen vectors?

Eigen vectors are important in many areas of mathematics and science. They are used in solving differential equations, understanding the behavior of dynamical systems, and in various fields of physics, such as quantum mechanics and fluid mechanics.

4. Can there be multiple eigen vectors for one eigenvalue?

Yes, there can be multiple eigen vectors for one eigenvalue. This is because the equation (A - λI)v = 0 has infinitely many solutions, so there can be more than one vector that satisfies it.

5. What is the difference between eigen vectors and eigenspace?

Eigen vectors are individual vectors that correspond to a specific eigenvalue. Eigenspace, on the other hand, is the set of all eigenvectors for a given eigenvalue. In other words, eigenspace is a vector space that contains all the eigen vectors for a particular eigenvalue.

Similar threads

  • Linear and Abstract Algebra
Replies
2
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
6
Views
1K
Replies
4
Views
3K
  • Linear and Abstract Algebra
Replies
10
Views
3K
  • Linear and Abstract Algebra
Replies
6
Views
6K
  • Linear and Abstract Algebra
Replies
5
Views
1K
  • Advanced Physics Homework Help
Replies
1
Views
894
  • Linear and Abstract Algebra
Replies
9
Views
2K
  • Calculus and Beyond Homework Help
Replies
13
Views
2K
Replies
1
Views
2K
Back
Top