- #1
DWill
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Homework Statement
An n x n matrix A is anti-symmetric if it satisfies the equation A^t = -A.
Show that if n is odd and A is anti-symmetric, then det(A) = 0. (Hint: carefully
use Theorem 3.5 on page 187.)
Homework Equations
Theorem 3.5: If B is obtained from A by multiplying a row (column) of A by a real number c, then det(B) = c det(A).
A^t = inverse of A
The Attempt at a Solution
I found the general 3x3 antisymmetric matrix to look like this:
[
0 a_12 a_13
-a_12 0 a_23
-a_13 -a_23 0
]
To find the determinant I just used the method of left and right diagonals since the matrix is 3x3, and I find it to be 0. BUT I don't know how to show this for any n x n matrix with n being odd (so it can be 5x5, 7x7, etc). I don't know where to use the theorem given in the hint either. Please help! Thanks