Question

Which of the relations given by the following sets of ordered pairs is a function?

O {(8, 1), (-4, 1), (3, 5), (0, 4), (-1, 2)}
O ((0, 3), (-6, 8), (-3, 5), (0, -3), (7, 11)}
O {(2, 4), (2, 6), (2, 8), (2, 10), (2, 12)}
O
{(-5,4), (-4,-3), (-3, -2), (-4, 5), (-2,-1)}

Answer 1

O {(8, 1), (-4, 1), (3, 5), (0, 4), (-1, 2)}

Explanation:

O {(8, 1), (-4, 1), (3, 5), (0, 4), (-1, 2)}

x-coordinates: 8, -4, 3, 0, -1

All x-coordinates are different, so this is a function.

O ((0, 3), (-6, 8), (-3, 5), (0, -3), (7, 11)}

0 shows up more than once as an x-coordinate, so this is not a function.

O {(2, 4), (2, 6), (2, 8), (2, 10), (2, 12)}

2 shows up more than once as an x-coordinate, so this is not a function.

O {(-5,4), (-4,-3), (-3, -2), (-4, 5), (-2,-1)}

-4 shows up more than once as an x-coordinate, so this is not a function.