Given the following matrix: 2 3 0 3 2 4 0 4 2 I'm having a difficult time working out the characteristic polynomial. I used the shortcut that I saw on YT, where it is (I am using x instead of lambda) X^3 - (trace) X^2 + (A11+A22+A33) X - DET(A) I got the following: trace is just 2+2+2 = 6 A11+A22+A33 = (4-16) + (4-0) + (4-9) = -13 DET(A) = -42 This is giving me a characteristic polynomial of X^3 - 6X^2 - 13X + 42. Using synthetic division with the correct e-vals, it just doesn't come out right. The correct roots/e-vals are -2, 2 and 4. Thanks.