1. Which of the following three vectors are parallel and which are perpendicular? U = (4, -6) v = (-2, 3) W = (9, 6) 2. If u = (3, 4) and v = (-2, 2), find: a. U . V b. 2(u . v) c. (2u) . v d. u . (2v) 3. If u = (3, 4), find: a. ju b. luz c. U . u 4. If 0 is the angle between u = (7, 1) and v = (5, 5), find: YA a. Ju b. [v 2- U= (4, 3) C. U . V d. 0 to the nearest degree 5. For the figure shown, find cos 0 (a) by using the dot product and (b) by us- ing right-triangle trigonometry. (Your Ov = (1, 0) 3 X answers should agree.) Ex. 5 Vectors and Determinants 443