. (19 TrueFalse: If A is one-to-one, then A is invertible. (2) True/False: It A is invertible, the the columns of A span a dimension n- 1 subspace of Rn. (3) TruexFalse: A can be row reduced to the n x n identity matrix if and only if A is onto. (4) True False: A is invertible if and only if A has n pivot positions. (5) True/False? If the determinant of A is negative, then A is not invertible. (6) Give an example of a subspace of IR2 that is not {0} or all of R2. X [:]