- #1

- 80

- 1

## Homework Statement

A =

7 -5 0

-5 7 0

0 0 -6

Can you please show your method aswell. Every time I try I get the wrong answer.

FYI Eigen values are 12.2,-6

## The Attempt at a Solution

so far I got:

det =

7-λ -5 0

-5 7-λ 0

0 0 -6-λ

Im unsure what to do next. I tried doing this

(7-λ) [(7-λ)*(-6-λ)] - (-5)(-5(-6-λ)) + 0 = 0

but when I expand and get a cubic equation and solve it, i dont get the right answer which is 12,2,-6