Proving Det(AB) = Det(A)Det(B) using Group Theory | Somy's Math Question

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In summary, a determinant is a value associated with a square matrix that can be used to determine various properties of the matrix, such as whether it is invertible or singular. Group Theory is a branch of mathematics that deals with the study of symmetry and the properties of groups, which are mathematical structures that describe symmetries. Group Theory is used to prove the equation Det(AB) = Det(A)Det(B) by applying the concept of group homomorphism to matrices A and B, which are elements of the general linear group GL(n). The general linear group GL(n) consists of all invertible n x n matrices with real entries and is a group under matrix multiplication. The key steps in proving Det(AB) = Det(A
  • #1
somy
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an emergency question!

Hi all.
I just wanted the proof of this statement via group theory:
det(AB)=det(A)det(B)
thanks in advance.
somy:smile:
 
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We don't do homework for you, you have to show your own work first and then we help you work through the rest. Please read the "sticky" thread at the top of the page.
 
  • #3
ok!
I just wanted to get an idea about it. I'll try it for myself.
Thank you
 

What is a determinant?

A determinant is a value associated with a square matrix that can be used to determine various properties of the matrix, such as whether it is invertible or singular.

What is Group Theory?

Group Theory is a branch of mathematics that deals with the study of symmetry and the properties of groups, which are mathematical structures that describe symmetries.

How is Group Theory used to prove the equation Det(AB) = Det(A)Det(B)?

In Group Theory, there is a concept called the group homomorphism which states that for two groups G and H, if there exists a homomorphism from G to H, then the order of the elements in G is preserved in H. This concept is applied to the matrices A and B, which are elements of the general linear group GL(n). By proving that there exists a group homomorphism from GL(n) to the set of non-zero real numbers, we can show that Det(AB) = Det(A)Det(B).

What is the general linear group GL(n)?

The general linear group GL(n) consists of all invertible n x n matrices with real entries. It is a group under matrix multiplication.

What are the key steps in proving Det(AB) = Det(A)Det(B) using Group Theory?

1. Prove that the determinant function is a group homomorphism from the general linear group GL(n) to the set of non-zero real numbers.2. Show that the determinant of the identity matrix is equal to 1.3. Prove that the determinant of a product of matrices is equal to the product of the determinants of each individual matrix.4. Combine these results to show that Det(AB) = Det(A)Det(B).

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