NTA Abhyas JEE Main2020MathematicsSets and RelationsPractice
The relation R given by x , y :   x 2 - 3 x y + 2 y 2 = 0 ,   ∀ x , y ∈ R is
Options
- Areflexive but not symmetric
- Bsymmetric but not transitive
- Csymmetric and transitive
- Dan equivalence relation
Correct answer
A. reflexive but not symmetric
Step-by-step solution
∵   x 2 - 3 x y + 2 y 2 = 0 ⇒ x 2 - x y - 2 x y + 2 y 2 = 0 ⇒ x x - y - 2 y x - y = 0 ⇒ x - 2 y x - y = 0 ⇒ x = y or x = 2 y Now, ∵ in R all ordered pairs x , x are present ∴ It is reflexive Now, 4 , 2 ∈ R as 4 = 2 2 but 2,4 ∉ R as 2 ≠ 2 4 ∴ It is not symmetric Also 4,2 & 2,1 ∈ R but 4,1 ∉ R ∴ It is not transitive