試題詳解

4.Let  R( A ) denote the column space of A, and N( A ) denote the null space of A. Which of the following statements are true?
(A) There exists a nonzero vector such that A^Ty = 0 and y = Ax for some  
(B) For every , we can always find some such that y = Ax.
(C) Let p be the orthogonal projection of
(D) Let y be a vector in  
(E) The intersection of R( A ) and N(A^T) is the empty set.