• ## Theia

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#### System no/infinitely many solution(s)

Hey!!

We have the matrix $A=\begin{pmatrix}1 & -1 & 0 \\ 1 & 0 & 1 \\ 0 & 1 & 1\end{pmatrix}$ and the vectors

mathmari Today, 18:07

#### Re: Show that A is identical

All good.

It may suffice to simply state that an $m\times m$ matrix of rank $m$ is invertible.
It's a property of matrices

Klaas van Aarsen Today, 16:29

#### Re: Show that A is identical

So is it as follows?

Since the rank of the $m\times m$ matrix $A$ is $m$ we have that at the echelon form the matrix has no

evinda Today, 16:18

#### Re: Show that A is identical

How about multiplying by $A^{-1}$?
$A$ is invertible isn't it?

Klaas van Aarsen Today, 15:53

#### Re: Show that A is identical

It is $0$ although neither $A$ nor $A-I$ is $0$.

How else can we get to the conclusion that $A=I$ ?

Do we use

evinda Today, 15:39