{(0, 1), (0, 5), (2, 6), (3, 3)} is not a function because zero is repeated in (0, 1),(0, 5)
While
{(1, 4), (2, 7), (3, 1), (5, 7)} is a function because there is no repetition in domain i.e. first element of each ordered pair is unique.
Step-by-step explanation:
To decide whether a relation is a function or not, the first elements of each ordered pair (domain) are observed. In order for a relation to be a function, there should be no repetition in first elements of each ordered pair.
In the given group of points:
{(0, 1), (0, 5), (2, 6), (3, 3)} is not a function because zero is repeated in (0, 1),(0, 5)
While
{(1, 4), (2, 7), (3, 1), (5, 7)} is a function because there is no repetition in domain i.e. first element of each ordered pair is unique.
This means we have to check the value of function against the value which is 6. First column is y. The last row of the the table shows y = 6 and the value of function at this value of y.