# What does "det" mean?

I'm new to physics and I see "det" used in math a lot. What does it mean?

SteamKing
Staff Emeritus
Homework Helper
It means to take the determinant of a matrix.

PFuser1232
Yeah, a matrix is a rectangular arrangement of numbers and the details means taking the determinant. Look up matrices and determinants on the net. Or better yet, there's a good course in linear algebra on iTunes u ( the one with Gilbert Strang) check it out

The "determinant" of a matrix is mostly used to solve systems of linear equations. It has multiple uses, but most notably, finding the determinant is a crucial step in inverting a square (##n \times n##) matrix. If you plan on pursuing high level math, physics, or engineering, you'll need to know what the determinant is and how to interpret it.

Borek
Mentor
finding the determinant is a crucial step in inverting a square (##n \times n##) matrix

Is it?

Mark44
Mentor
finding the determinant is a crucial step in inverting a square (##n \times n##) matrix
Borek said:
Is it?
I agree with Borek here (in his questioning of your statement about the determinant being a crucial step in inverting a matrix.

Certainly if det(A) = 0, the inverse of A doesn't exist, but for an invertible matrix A, you can find the inverse using Gauss-Jordan without ever taking the determinant. If it turns out that A isn't invertible, the Gauss-Jordan process will end up with a matrix with one or more rows of zeros (instead of the identity matrix) on the left side of your augmented matrix.

That makes sense. I'm a first-year undergrad and the highest level of math I've had is linear algebra, so I'm just pulling out of the bag of tricks I have so far. Thanks for pointing that out.