# Thread: Hi, I am a graduate student and need help with some Linear Algebra.

1. ## Hi, I am a graduate student and need help with some Linear Algebra.

I have a matrix C = {[1,1],[0,1],[1,0]}. And C^T (Transpose) = {[1,0,1], [1,1,0]}

When I multiply C*C^T, I get {[2,1,1],[1,1,0],[1,0,1]}

The question: What is the interpretation of the diagonal entries of C*C^T? My guess is they are the eigenvalues

When I multiply C^T*C, I get {[2,1],[1,2]}

Question: What do the entries of C^T*C represent? My guess is they are the eigenvectors

There is no book for this class, so I need help, please!

2. ## Re: Hi, I am a graduate student and need help with some Linear Algebra.

First what does 'interpretation' mean here? Did you actually calculate the eigenvalues of C*C^T or the eigenvectors of C^T*C? They don't look to me like they have anything to do with the diagonal entries of those matrices.

3. ## Re: Hi, I am a graduate student and need help with some Linear Algebra.

I think I figured it out. We are looking at term-document matrices.