Math 180 solution to quiz #1b: cole. Consider the points a( 3, 2, 1), b(5, 0, 2), and c(6, 1, 3). Check: u = ab = h5 + 3, 0 2, 2 + 1i = h8, 2, 3i v = ac = h6 + 3, 1 2, 3 + 1i = h9, 1, 4i. and w = u v. = h( 2) 4 3 ( 1), 3 9 8 4, 8 ( 1) ( 2) 9i. = 5h 1, 1, 2i. w u = 5( 8 + 2 + 6) = 0 x w v = 5( 9 + 1 + 8) = 0 x.