Solution
= Solution
The <determinant> is invariant under <transpose>, while multiplying all $n$ rows by $-1$ multiplies it by $(-1)^n$. Thus, for <odd integer> $n$,
$$
\det A=\det A^\top=\det(-A)=(-1)^n\det A=-\det A.
$$
Over the <real numbers>, this forces \b[$\det A=0$], so $A$ is a <singular matrix>. This is the <odd-dimensional skew-symmetric singularity theorem>.