Let A be an n x n (square) matrix and let x and y be vectors in all real numbers. Show that if Ax=Ay and x does not equal y, then the matrix A must be singular.
How do I start on this problem?
That's the problem, I never learned how to prove a matrix is nonsingular or singular. I know what they mean, that they have an inverse or don't.
Are you saying that I should try to show that it has an inverse? Or can I just do this by trying to find a determinate which is zero?