Question: In Exercises, use the fact that four points with position vectors p, q, r, and s will be coplanar if the vectors p - q, p - r, and p - s are coplanar to find which sets of points all lie in a plane.
Exercise: a. (1, 1, -1), (-3, 1, 1), (-1, 2, -1), (1, 0, 0).
b. (1, 2, -1), (2, 1, 1), (0, 1, 2), (1, 1, 1).
c. (0, -4, 0), (2, 3, 1), (3, -4, -2), (4, -2, -2).
d. (1, 2, 3), (1, 0, 1), (2, 1, 2), (4, 1, 0).