Question

Determine which relation is a function.

A.{(–4, 3), (–2, 3), (–1, 2), (2, 5), (3, 2)}

B.{(–4, 1), (–2, 3), (–2, 1), (–1, 5), (3, 2)}

C.{(–4, 1), (–2, 3), (–1, 2), (3, 5), (3, 2)}

D.{(–4, 1), (–2, 3), (–1, 1), (–1, 5), (3, 2)}

Answer 1

The A is a function, because all the values of the independent variable (the first value of the ordered pairs) are related to only one value, i.e. have only one image.

In B - 2 has two different images: 3 and 1. That makes that this is not a function.

In C, 3 has two different images: 5 and 2. That makes that this is not a function.

In D, - 1 has two different images: 1 and 5. That makes that this is not a function.