# Eigenvalues lambda question

1. Jun 25, 2008

### rocomath

Assuming 2 by 2.

Ok, I'm asked to find the Eigenvalues. How do I know which should be lambda 1 and lambda 2? I can find the lambda's easily, but does it matter which is 1 or 2? It becomes important when I'm asked to diagonalize.

$$A=S\Lambda S^{-1}$$

Last edited: Jun 25, 2008
2. Jun 25, 2008

### matt grime

Re: Eigenvalues

The order is not important when you diagonalize.

3. Jun 25, 2008

### rocomath

Re: Eigenvalues

Thanks matt! Now I can go back to studying :)

4. Jun 25, 2008

### HallsofIvy

Staff Emeritus
Re: Eigenvalues

Swapping $\lambda_1$ and $\lambda_2$ will swap their positions on the diagonal but either way is a valid diagonalization.