Row reduced echelon form: Ax=0 has only 1 soln iff in every column of R has leading

CStudent

New member
Joined
Nov 16, 2018
Messages
14
Hey.

I have the following question to solve:

* Given a matrix A that is size m x n and m>n.
Let R be the RREF that we get by Gaussian elimination of A.
Prove that the system equation Ax=0 has only one solution iff in every column of R there is a leading element.

I have some answer of intuition so I'm not really sure,
Let's assume that we had R with some free variable, and we know(?) that any free variable has a degree of freedom which means that it yields infinite number of solutions.

Now, I am not sure again about the establishment of this proof and to what extent it's accurate. Moreover, I am not if it proves the point of iff (equivalence).

Thank you!
 
Last edited by a moderator:
Top