Question

If c is a skew-symmetric matrix of order n and x is n  1 column matrix, then xt cx is a

Answer 1

up vote0down voteaccepted

The term X′AX is also∑k,lxkAk,lxl

which is, when reversing the variables of summation,∑k,lxlAl,kxk=X′A′X

your mistake is that (CD)T is DTCT, not CTDT.