Yukinoshita
New member
- Joined
- Nov 6, 2021
- Messages
- 3
Suppose A is a n*m matrix ,B is a m*n matrix (n>=m) . If AB=I , proof:
1) m=n
2) A,B are both invertible.
I can try to use some special cases to illustrate it, but I think use some rank theorem may be helpful.
Can anyone help me? Thanks a lot!
1) m=n
2) A,B are both invertible.
I can try to use some special cases to illustrate it, but I think use some rank theorem may be helpful.
Can anyone help me? Thanks a lot!
