Question

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

• A. a pair of perpendicular lines
• B. a pair of parallel lines
• C. a pair of parallel planes
• D. a pair of perpendicular planes

Answer 1

Answer: (D)

a pair of perpendicular planes

Answer 2

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