Q. The locus represented by $xy + yz = 0$ is

KCET KCET 2018Three Dimensional Geometry

A

a pair of perpendicular lines

B

a pair of parallel lines

C

a pair of parallel planes

D

a pair of perpendicular planes

Solution:

Locus represented by xy + yz = 0 $\Rightarrow$ $y(x + z) = 0$
The planes y = 0 and x + z = 0 are perpendicular