Formula for finding number of relations is

Number of relations = 2 Number of elements of A × Number of elements of B

 


Where does it come from?

 

We know that

Relation is a subset of Cartesian product A × B

 

Number of relations = Number of subsets of A × B

Using Formula,
Number of subsets  = 2 Number of elements of set

            = 2 Number of elements of A × B

 

Now,

We know that

Number of elements of A × B

   = Number of elements of A × Number of elements of B

 

Thus,

Number of relations = 2 Number of elements of A × B

  = 2 Number of elements of A × Number of elements of B

  1. Chapter 2 Class 11 Relations and Functions
  2. Concept wise
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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 7 years. He provides courses for Mathematics and Science from Class 6 to 12. You can learn personally from here https://www.teachoo.com/premium/maths-and-science-classes/.
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