Class 11 Maths Chapter 2
Relations and Functions – Flash Cards
Flash Card 1: What is a Relation?
A relation from set A to set B is a subset of A × B.
Example: If A = {1,2} and B = {a,b}, then {(1,a),(2,b)} is a relation.
Flash Card 2: Cartesian Product
A × B = {(a,b) : a ∈ A and b ∈ B}
Number of elements = n(A) × n(B)
Flash Card 3: Types of Relations
Empty Relation: No element is related.
Universal Relation: All elements are related.
Identity Relation: Every element relates to itself.
Flash Card 4: Reflexive Relation
A relation R on set A is reflexive if (a,a) ∈ R for every a ∈ A.
Flash Card 5: Symmetric Relation
R is symmetric if (a,b) ∈ R ⇒ (b,a) ∈ R.
Flash Card 6: Transitive Relation
R is transitive if (a,b) ∈ R and (b,c) ∈ R ⇒ (a,c) ∈ R.
Flash Card 7: Equivalence Relation
Relations and Functions – Flash Cards
Flash Card 1: What is a Relation?
A relation from set A to set B is a subset of A × B.
Example: If A = {1,2} and B = {a,b}, then {(1,a),(2,b)} is a relation.
Flash Card 2: Cartesian Product
A × B = {(a,b) : a ∈ A and b ∈ B}
Number of elements = n(A) × n(B)
Flash Card 3: Types of Relations
Empty Relation: No element is related.
Universal Relation: All elements are related.
Identity Relation: Every element relates to itself.
Flash Card 4: Reflexive Relation
A relation R on set A is reflexive if (a,a) ∈ R for every a ∈ A.
Flash Card 5: Symmetric Relation
R is symmetric if (a,b) ∈ R ⇒ (b,a) ∈ R.
Flash Card 6: Transitive Relation
R is transitive if (a,b) ∈ R and (b,c) ∈ R ⇒ (a,c) ∈ R.
Flash Card 7: Equivalence Relation
