Prove that $AA^+x=x$ for $\forall x \in range(A)$

60 Views Asked by At

How can I prove that $AA^+x=x$ for any vector $x \in range(A)$, where $A$ is a non-zero matrix?

1

There are 1 best solutions below

0
On BEST ANSWER

Since $x \in range(A)$, $x=Ay$ for some $y$.

$$AA^+x=AA^+Ay=Ay=x$$

since $AA^+A=A.$