For real numbers x and y, define xRy if and only if x - y + π is an irrational number. Then the relation R is
For real numbers x and y, define xRy if and only if x - y + π is an irrational number. Then the relation R is Correct Answer Reflexive
Concept:
A relation R in A is said to be:
- Reflexive if aRa, ∀ a ∈ A.
- Symmetric if aRb ⇒ bRa, ∀ a, b ∈ A.
- Transitive if aRb and bRc ⇒ aRc, ∀ a, b, c ∈ A.
- Any relation which is reflexive, symmetric and transitive is called an equivalence relation.
Calculation:
Let's check the given relation for its type one by one.
Reflexive: xRx = x - x + π = π, which is irrational. Therefore, R is reflexive.
Symmetric: Let's say that xRy is true i.e. x - y + π is irrational. Now, yRx = y - x + π will not always be irrational.
For x = 2π, y = π
⇒ x - y + π = 2π - π + π = 2π → Irrational number
⇒ y - x + π = π - 2π + π = 0 → rational number
So, the relation is not symmetric.
Transitive: If π R 1 and 1 R 2π are true, then π R 2π = π - 2π + π = 0 is rational. Therefore, R is not transitive.
Since the relation R is reflexive but not symmetric and transitive.