試題詳解

3. Suppose D=AB with Which of the true?
(A) Null Space of D = Null Space of B if and only if a≠5.
(B) Column Space of D = Column Space of A if and only if b≠2.
(C) There exists values of a, b such that Rank of D=1.
(D) Rank of D=2 only if a=5 and b=2.
(E) Rank of D=3 only if a≠5 and b≠2.