2
$\begingroup$

Possible Duplicate:
If $AB = I$ then $BA = I$

I'm trying to remember the one line proof that for square matrices $AB = I$ implies $BA = I$. I think it uses only elementary matrix properties and nothing else. Does anyone know the proof?

I remember it beginning with $BAB = B$ and the result following almost immediately.

  • 1
    What are elementary matrix properties?2012-06-01

2 Answers 2