Determine if the following pairs of lines are orthogonal.
(a) The line through
P = (1, 0,
−3) with direction vector (
−1,
2, 1) and the line through
Q = (0,
3, 1) with direction vector (
2, 1,
−1).
(b) The line through
P = (
−1,
3, 2) with direction vector (0,
−2,
−2) and the line through
Q = (0,
2, 1) with direction vector (
2, 1,
−1).
(c) The line through
P = (2, 1,
2) with direction vector (
−1, 2, 1) and the line through
Q = (0, 5,
4) with direction vector (1, 1,
−1).