) 2.'1'52 1. Let V = R? and let H = To cxy, 79 R . Is H a subspace of the vector space V7 31[71 Give a proof or disprove by counterexample. 2. Let V = R? and let H be the subset of V of all points on the plane 3z + z = 0. Is H a subspace of the vector space V7 Give a proof or disprove by counterexample. 3. Let V = R? and let H be the subset of V of all points in the first and fourth quadrant. That is, H = {(z,y) : # > 0}. Is H a subspace of the vector space V7 Give a proof or disprove by counterexample