# What does "det" mean?

1. Nov 7, 2014

### Sicktoaster

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

2. Nov 7, 2014

### SteamKing

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

3. Nov 12, 2014

### UncertaintyAjay

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

4. Nov 21, 2014

### AMenendez

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.

5. Nov 21, 2014

### Staff: Mentor

Is it?

6. Nov 21, 2014

### Staff: Mentor

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.

7. Nov 22, 2014

### AMenendez

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.