Find the area of a parallelogram formed by the vectors PQ and PR, where P = (-6, 3, −3), Q = (-5, -6, 4) and R = (6, 1, 1).

Consider the vector v=(1,3,0,4). Find u such that a u has the same direction as v and one-half of its length. b u has the direction opposite that of v and twice its length.