(10 pts) Find a unit vector with positive first coordinate that is orthogonal to the plane through the points P = (-5, 1, 5), Q = (-1, 5, 9), and R = (-1, 5, 11). Solution cross product i j k 4 4 4 4 4 6 =>i(24-16) - j(24-16) + k(0) =>8i - 8j is vector perpendicular to plane unit vector : (i - j)/2 it has +ve first cordinate hence answer is (1/2 , 1/2 , 0) please rate.