Question

how do I find the determinant of a matrix?

Answer 1

You have to take the numbers before the x variables and y variables. Like this:

x1 y1 (from first equation)

x2 y2 (from second equation)

With those huge brackets, then you cross multiply, you have to start with x1* y2
Then x2 * y1

Then you take the two products and subtract it like this. It has to be put this way:

(x1*y2) - (x2 * y1) = ?

That is how you solve for the determinant.

Answer 2

that's just for a matrix of size 2...

what if we have a matrix of size 3, or of size 4..... what about a matrix of size n?

Answer 3

Ok well here are some help websites for that:

http://www.ee.buffalo.edu/faculty/paololiu/edtech/roaldi/References/matrix.htm

http://www.ehow.co.uk/video_4755242_solving-matrix.html

http://hotmath.com/hotmath_help/topics/solving-matrix-equations.html


and looking for more help on google too, I hope these websites work and help you, cause im not to fond of matrices.

Answer 4

I'm afraid none of those can tell me how to find the determinant of a matrix of size n :-P

Answer 5

Oh man, repost your question this way someone else with experience of matrices can answer that. I'm really sorry I couldn't help.

Answer 6

I'm afraid nobody can help me :( even the local doctor of mathematics on this website doesn't know how to find the determinant of even a 4x4 matrix

Answer 7

have you tried google?

Answer 8

just use cofactor expansion...or use elementary matrices to reduce the matrix to ref

Answer 9

What are you talking about here ... it's quite straight forward ... I'll be amazed if it's not in the wikipedia definition.

Or better any decent undergrad text book in linear algebra.

Answer 10

my calculator can't do it :-(

Answer 11

Like this one:
http://www.amazon.com/Introduction-Linear-Algebra-Fourth-Gilbert/dp/0980232716/ref=sr_1_1?s=books&ie=UTF8&qid=1318959082&sr=1-1

Answer 12

do it by hand

Answer 13

wait it can! it has a det() function

Answer 14

Strang is 'The Man'!