Determinant of Skew-Symmetric Matrix: Is it Zero for Odd n?

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SUMMARY

The determinant of a skew-symmetric matrix A is zero when the matrix size n is odd. This is established by the property that Det(A) = Det(AT) and the relationship Det(-A) = -Det(A) for odd n. Consequently, if Det(A) = Det(-A), it follows that 2Det(A) = 0, leading to the conclusion that Det(A) must equal zero. This property does not hold for even n, where the determinant can be non-zero.

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Homework Statement



A square (nn) matrix is called skew-symmetric (or antisymmetric) if AT =
-A. Prove that if A is skew-symmetric and n is odd, then detA = 0. Is this true
for even n?

Homework Equations


Det(A) = Det(AT) where AT= the transpose of matrix A


The Attempt at a Solution


I started to try and say that since AT=-A then Det(AT) = Det(-A) so Det(A) = Det(-A) b/c the law that Det(A)=Det(AT) but I didnt know where to go from here.. specifically what impact does the odd number of n have to do with anything.. Any help
 
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and I assume that I need to say that Det(-A) = -Det(A) for the odd number on n so then I could conclude 2Det(A)=0 but i don't see why: Det(-A) = -Det(A) is true for odd number n matrices
 
You can easily calculate det(-I), no?? (where I is the identity matrix)
Then you can write det(-A)= det((-I)A).
 

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