- Singular value decomposition exists for all rectangular matrices
 - A square is a rectangle
 - LR , LQR, LU may not exist for some matrices
 - All matrices are basically rotation and stretching.
 - A = ULV'
 - U and V are rotations
 - L is the scaling
 - L square will have the eigen values of AA'
 - U and V are orthonormal matrices, so their inverse and transpose are same