Question
Question: The equation xy = 0 in three dimensional space represents –...
The equation xy = 0 in three dimensional space represents –
A
a pair of straight lines
B
a plane
C
a pair of planes at right angles
D
a pair of parallel planes
Answer
a pair of planes at right angles
Explanation
Solution
xy = 0 Ы x = 0 or y = 0. Hence locus of xy = 0 is the union of all points which lie in YOZ-plane or on ZOX-plane. So the equation xy = 0 represents a pair of perpendicular planes.