# Homework Help: Eigenvalues ?

1. Apr 19, 2010

### cragar

1. The problem statement, all variables and given/known data

This is probably a really simple question , but how do i test my eigen values to see if there right ,---------- (A-tI)x=0 where t is an eigen value , I know how to test if my eigen vectors are correct but how do i test to see if my eigen values are right , before i find my eigen vectors.

2. Apr 19, 2010

Well, if you solved your characteristic equation correct, then your eigenvalues should be correct. I don't know how you could check them before solving the eigenvalue problem and using the eigenvectors. Eigenvalues have some certain properties, but I don't see how they could help you determine if you're right.

3. Apr 19, 2010

### Matterwave

I think you're going to have to calculate the Eigenvectors and then check to see if they are both right.

Otherwise, you can check your answers using a calculus-enabled program like Maple.

4. Apr 19, 2010

### cragar

ok thanks , so when i find my eigen values and eigen vectors i can use
Ax=tx to see if they are both right .

5. Apr 19, 2010