3. (2 marks) Explain why a b C d E M2x2 (R) : d = a2 is not a vector space. 4. (3 marks) Show that V = {p(x) E P2(R) : p'(1) = 0} is a subspace of P2 (). 5. (3 marks) Are the following three vectors in 3 2 DO U1 = 02 = 2 03 = linearly independent? Justify your