(6.1) Assume that A is a square matrix with a row of zeros. Prove that A is singular. (3) (6.2) Assume that A and B are matrix of the same size. Prove or Disprove that (A B) (3) 2 is a symmetric, skew-symmetric or neither. (6.3) Find the condition (if possible) for which (AA (4) t ) t and (A A t ) t would be sy