If A is a square matrix then A−¯¯¯¯¯¯¯AT is a skew hermitian matrix.
True
Lets take general element from matrix A and verify if A−¯¯¯¯¯¯¯AT is a skew hermitian matrix.
Assume
aij = p + iq
aji = r + is
The expression A−¯¯¯¯¯¯¯AT will translate to aij−¯¯¯¯¯¯¯aji at the elementary level in the resultant matrix.
If mij is the ijth element in resultant matrix
mij=aij−¯¯¯¯¯¯¯aji=(p+iq)−(r−is)
=(p – r)+ i (q + s) ….(1)
mji=aij−¯¯¯¯¯¯¯aij=(r+is)−(p−iq)
= r – p + i (q+s) ….(2)
From (1) & (2) we can see that
mij=−¯¯¯¯¯¯¯¯¯mji
This implies that the resultant matrix or A−¯¯¯¯¯¯¯AT is skew hermitian.