試題詳解

1. Let

be the reduced row echelon form of a matrix A = [a1 a2 a3 a4 a5]. Which of the following statements is/are true?
(A) a2 is the 4 × 1 zero vector.
(B) The three column vectors a1, a4 and a5 are linearly independent.
(C) The column space of R is the same as the column space of A.
(D) Let B = [a1 a2 a3] be a submatrix of A. The reduced row echelon form of B is not always a submatrix of R.
(E) None of the above is true.