Which of these are subspaces? 1. S = R5 T = {x : x4 =0, x5 = 0} 2. S = R5 T = (x : * =1, 25=1} 3. S = C([0, 1]) (bounded, continuous functions on [0, 1]) T = {polynomials of degree at most p} 4. S = continuous functions on the real line T = {f(t) : f is bandlimited to } 5. S = RN T = fac : a has no more than 5 non-zero components} 6. S = RN T= (a : c'x=3}, where cc R~ is a fixed vector (Recall the standard dot product c x = En- cln]x)