Question

Which of the following represents a function?

Answer 1

A.

Explanation:

in order for a function to be a function, one input must only have one output.

We see that in option B, -1 has two outputs (10, 18)

In option c, we see that -4 has two outputs (2, -2)

In option D, we see that -3 has two outputs (5, 0)

This means A is the correct option because each input has only one output.