5
1
3
1
1




=
−
−




−


 is a symmetric matrix as A′ = A
Definition 5 A square matrix A = [aij] is said to be skew symmetric matrix if
A′ = – A, that is aji = – aij for all possible values of i  and j Now, if we put i = j, we
have aii = – aii Therefore 2aii = 0 or aii = 0 for all i’s This means that all the diagonal elements of a skew symmetric matrix are zero