Giving max points and brain thing
Determine whether the relations are functions.
YES
NO
{(1, 1), (2, 2), (3, 3), (4,4)}
{(1,2), (3, 4), (5, 6), (1, 3}
{(1, 6), (9, 3), (6, 1), (3, 9)}
{(7,5), (-3, 7), (-7, 5), (-3,5)}
