Question

Anyone know of a good way to find the answer to det[x+5 4 4],[-4 x-3 -4], [-4 -4 x-3] = 0

Answer 1

Read this, be happy: http://en.wikipedia.org/wiki/Rule_of_Sarrus

Answer 2

It involves a bit of algebra and keeping track of your terms, but it's a quick and easy way to compute the determinant without a whole lot of hassle.

Answer 3

ok thanks, I kind of knew that rule, but I was wondering if there was something I was missing, something that would make it easier, but perhaps it's as easy as it will get, it's just the x's complicate things

Answer 4

Yeah, no computation of the determinant of a 3x3 matrix with variables will ever be easy. :/ Sorry, it's just one minor tedious thing that eventually, you can leave to a calculator. xD

Answer 5

ahh k thanks a lot for your help

Answer 6

If not you should get x1 = 3 and x2 = -1

if I haven't miscalculated.