(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Consider an n x m matrix A with n >= m. If all columns of A are orthonormal, then A'A = I. What can you say about AA'?

Where A'A = transpose(A)*A and AA' = A*transpose(A)

2. Relevant equations

3. The attempt at a solution

For the case that n = m:

A is square. Since the columns of A are normalized, and the set of vectors contained in A is orthogonal, we can call A orthogonal.

So, A'A = I and AA' = I

For the case that n > m:

I'm lost here...

any hints? What should I be looking up in the books to understand this?

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# A*transpose(A) for orthonormal columns ?

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