JEE Main 2019 Mathematics question

Mathematics Three Dimensional Geometry JEE Main 2019

If the lines x = ay + b, z = cy + d and x = a′z + b′, y = c′z + d′ are perpendicular then:

(A)cc′ + a + a′ = 0
(B)aa′ + c + c′ = 0Correct
(C)bb′ + cc′ + 1 = 0
(D)ab′ + bc′ + 1 = 0

Answer: (B)

Solution

Directions (a, 1, c) and (a′, c′, 1): aa′ + c′ + c = 0.

Question ID VK-010000