10 2022 档案

$AB = I$ implies $BA = I$
摘要：Suppose $AB=I$. Then $\det B\ne0$, so $\exists C,BC=I$ (think elementary column operations). Now $ABC=A$, so $C=A$. 阅读全文
posted @ 2022-10-21 17:14 王子睿 阅读(93) 评论(0) 推荐(0)