Let A = {2, 3, 5} and R = {(2, 3), (2, 5), (3, 3), (3, 5)}. Show that R is a binary relation on A. Find its domain and range.

First, calculate A×A.


A×A = {(2, 2), (2, 3), (2, 5), (3, 2), (3, 3), (3, 5), (5, 2), (5, 3), (5, 5)}


Since, R is a subset of A × A, it’s a binary relation on A.


The domain of R is the set of first co-ordinates of R


Dom(R) = {2, 3}


The range of R is the set of second co-ordinates of R


Range(R) = {3, 5}


1