CBSE Class 12 Maths Notes Chapter 1 Relations and Functions Relation: A relation R from set X to a set Y is defined as a subset of the cartesian product X × Y. We can also write it as R ⊆ {(x, y) ∈ X × Y : xRy}. Note: If n(A) = p and n(B) = q from set A to set B, then n(A × B) = pq and number of relations = 2pq. Types of Relation Empty Relation: A relation R in a set X, … [Read more...]