Under which one of the following conditions are the lines x = ay + b; x = ey + f; z = gy + h perpendicular?

If î = i – j + k̂, ĵ = 2î + 3ĵ + 2k̂…

The line passing through the points (1, 2, -1) and (3, -1, 2) meets the…

The points P(3, 2, 4), Q(4, 5, 2), R(5, 8, 0) and S(2, -1, 6)…

(0, 0, 0), (a, 0, 0), (0, b, 0) and (0, 0, c) are four…

A straight line with direction cosines (0, 1, 0) is