# Eigenvector question^^

1. Nov 15, 2005

### johnnyboy2005

hey, not sure how this works on this web site but was just wondering if someone can tell me if i'm doing this right....

find characteristic equation of matrix

A=l 4 0 1 l
l -2 1 0l
l -2 0 1l

i found it to be (L=lambda)...

L^3 - 6L^2 + 11L - 6 = 0

only because i solved the matrix det(LI - A) and found that

=(L-4)[(L-1)(L-1)] -1[0 - (2)(L-1)] ...have i got this right? thanks for the help

2. Nov 15, 2005

### saltydog

Yes, that's right. Or just say:

$$x^3-6x^2+11x-6=0$$

We use a formatting language called LaTex to format it in traditional form:

$$M=\left( \begin{array}{ccc} 4 & 0 & 1 \\ -2 & 1 & 0 \\ -2 & 0 & 1 \end{array} \right)$$

If you choose to post frequently here you may wish to learn it. Start by looking at the "General Physics" forum, top thread titled "Introducing LaTex".