मराठी

Types of Relations

Advertisements

Topics

Estimated time: 7 minutes
CBSE: Class 12

Types of Relations

Type Definition Small Example
Empty Relation A relation in which no element of A is related to any element of (A), i.e. \[(R=\phi)\]. A={1,2}, \[R=\phi\]
Universal Relation A relation in which every element of A is related to every element of A, i.e. \[R=A \times A\]. A = {1,2}, R = {(1,1),(1,2),(2,1),(2,2)}
Identity Relation A relation in which every element is related only to itself, i.e. \[I_A={(a,a):a\in A}\]. A={1,2}, \[I_A={(1,1),(2,2)}\]
Reflexive Relation A relation R on A is reflexive if \[(a,a)\in R\] for every \[a\in A\]. R={(1,1),(2,2),(1,2)}
Symmetric Relation A relation R on A is symmetric if \[(a,b)\in R \Rightarrow (b,a)\in R\]. R={(1,2),(2,1)}
Transitive Relation A relation R on A is transitive if \[(a,b)\in R\] and \[(b,c)\in R \Rightarrow (a,c)\in R\]. R={(1,2),(2,3),(1,3)}
Equivalence Relation A relation is called an equivalence relation if it is reflexive, symmetric, and transitive. “Is equal to” relation
CBSE: Class 12

Key Points: Types of Relations

  • Empty relation and universal relation are called trivial relations.

  • Identity relation always contains all self-pairs and is always reflexive.

  • To check reflexivity, see whether every (a,a) is present in the relation.

  • To check symmetry, see whether every (a,b) has the reverse pair (b,a).

  • To check transitivity, see whether (a,b) and (b,c) together give (a,c).

  • A relation is an equivalence relation only when all three properties—reflexive, symmetric, and transitive—are satisfied together.

Shaalaa.com | Relations and Functions part 2 (Empty Relation)

Shaalaa.com


Next video


Shaalaa.com


Relations and Functions part 2 (Empty Relation) [00:08:49]
S
Series: 1
0%


Advertisements
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×