Question

Which relation is a function? 
I. {(2, 4), (1, 7), (3, 0), (5, 4)} 
II. {(3, 6), (3, 6), (8, 6), (8, 10)} 
III. {(4, 1), (2, 5), (8, 3), (4, 6)}

Answer 1

A  function  is a special type of relation in which each element of the domain is paired with exactly one element of the range.

|) The relation { (2, 4), (1, 7), (3, 0), (5, 4) }

The relation is  a function because the each element of the domain is paired with exactly one element of the range.

||)The relation { (3, 6), (3,6), (8, 6), (8, 10) }

The relation is  not a function because the  element (8) of the domain is paired with  two elements of the range (6 and 10).

|||) The relation { (4, 1), (2, 5), (8, 3), (4, 6) }

The relation is  not a function because the  element (4) of the domain is paired with  two elements of the range (1 and 6).