Matrix determinant operator commutative?

In summary, when working with determinants of matrices, the determinant of the product of any number of matrices is equal to the determinant of each individual matrix, regardless of the order in which the factors are multiplied. This property is known as (multiplicative) distributivity for the determinant and is possible because the determinant operator is commutative in its target space. Therefore, matrix multiplication is commutative when working with determinants. However, it should be noted that this property only holds for square matrices.
  • #1
el_llavero
29
0
I've been going through properties of determinants of matrices and found the following:

Assuming products are defined and the matrices involved are nonsingular of the same order

The determinant of the product of any number of matrices is equal to the determinant of each matrix; where the order of factors does not matter

det(AB)=det(A)det(B)
det(AB)=det(B)det(A)
det(BA)=det(A)det(B)
det(BA)=det(B)det(A)

det(ABC)=det(C)det(A)det(B)

det(ACB)=det(A)det(B)det(C)

Is this correct? And is there a way to describe this property regarding commutatively? I know in general matrix multiplication is not commutative unless the matrices involved are diagonal and of the same dimension. However the determinant operator seems to not preserve the non commutative property of matrix multiplication, on either side of the equality. What I’m looking for here is a formal way of describing this property that encompasses the fact that order of factors does not matter and if commutativity should be used in any part of this description. Is matrix multiplication commutative?
 
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  • #2
Probably (multiplicative) distributivity for the determinant together with commutativity of it's target space are the terms you are looking for.
 
  • #3
Thanks, that makes sense. Can you explain a bit more why is matrix multiplication commutative?
 
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  • #4
Something isn't completely accurate in the second sentence of the original post

"Assuming products are defined and the matrices involved are nonsingular of the same order"

since it doesn't matter if the matrices are nonsingular for this property to hold a more accurate statement would be

"Assuming products are defined and the matrices involved are square matrices"
 

What is a determinant?

A determinant is a mathematical operation performed on a square matrix that results in a single number. It is used to determine various properties of the matrix, such as invertibility and solutions to systems of linear equations.

What is the matrix determinant operator commutative property?

The commutative property states that the order in which two operations are performed does not affect the final result. For the matrix determinant operator, this means that the order of the matrices being multiplied does not change the determinant value.

Why is the matrix determinant operator commutative property important?

The commutative property is important because it allows for simpler and more efficient calculations. By knowing that the determinant operator is commutative, we can rearrange the order of the matrices and still get the same result, saving time and effort.

Is the matrix determinant operator always commutative?

No, the matrix determinant operator is only commutative for square matrices. For non-square matrices, the order of multiplication does affect the determinant value.

How is the matrix determinant operator commutative property related to other properties of determinants?

The commutative property is one of several properties of determinants, including the distributive and associative properties. These properties allow for easier manipulation of determinants and make them a powerful tool in linear algebra.

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