Matrix multiplied by its transpose

Question

I've just done a matrix multiplication question and an interesting thing popped up. That is $MM^T=symmetric $ for the specific matrix we were given. Is this a general property or something special?

Being symmetric is something special for $MM^T$, see this question. In general, $MN$ is not symmetric. — Dietrich Burde, May 11 '18 at 15:13

score 2 · Answer 1 · answered May 11 '18 at 15:13

2

It is general:$$(MM^T)^T=(M^T)^TM^T=MM^T.$$

answered May 11 '18 at 15:13

José Carlos Santos

427,504

Matrix multiplied by its transpose

1 Answers1