Can the Determinant of Similar Matrices be Proven Equal?

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SUMMARY

If matrices A and B are similar, then their determinants are equal, formally expressed as det(A) = det(B). This is proven using the definition of similar matrices, where B can be represented as B = S-1AS for some invertible matrix S. The determinant property states that det(B) = det(S-1)det(A)det(S), which simplifies to det(B) = det(A) since det(S-1S) equals det(I), the identity matrix. This proof demonstrates a fundamental property of determinants in linear algebra.

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  • Understanding of matrix operations and properties
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Dustinsfl
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Show that if A and B are similar matrices, then the det(A)=det(b).

I am not entirely sure how to start this proof.
I was thinking...
A=ai j

det(A)=\sumai j*(-1)i+j*Mi j from j=1 to n.

I am pretty much clueless on this one though and not sure if I am just throwing stuff on the wall hoping something will stick
 
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Write down the definition of similar matrices. What do you know about determinants that you can apply to that equation?
 
Matrix A is similar to B if there exists S such that B=S-1*A*S
 
det(B)=det(S-1*A*S)=det(S-1)det(A)det(S)=det(S-1*S)det(A)=det(I)det(A)=det(A) thus, det(B)=det(A)

Remarkable easy.
 
Good job!
 

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