Question

Which of the following relations represents a function?

{(4,2), (4,3), (4, 5), (4,7)}
{(-2, 1), (0,5), (1, -3), (-2, 0)}
{(-1, 3) (-2, 3) (-1, 5) (-2,5)}
{(-3, 1), (1, 4), (-2, 1), (0, 3)}

Answer 1

{(-3, 1), (1, 4), (-2, 1), (0, 3)}

Explanation:

If a set of ordered pairs represents a function, then there must not be any first coordinate that repeats itself more than once in any of the ordered pairs.

In other words, no x-coordinate should correspond to more than one y-coordinate.

From the given options, the only set of ordered pairs that satisfies the conditions of a function is;

{(-3, 1), (1, 4), (-2, 1), (0, 3)}

The correct answer is the last option.