does Ainverse*D*A will get D OR I HAVE TO MULTIPLE THE THREE MATRICES TOGHETHER
Hi,
generally, matricies do not commute (exemple of non-commutativity are the words were the object are letters and the operation is concatenation (put together in order) : putting a,r,c together can given words like car or arc but car is not the same as arc even if they use the same letters)
the same way Ainverse D A is not always the same as D A Ainverse (= D) and so Ainverse D A is not always the same as D because D A Ainverse = D.