Relations Examples Page 1

What are the domain and range of the relation {(2, 19), (5, 4), (3, 17), (11, 4)}?

The domain is

{2, 5, 3, 11}

and the range is

{19, 4, 17}.

Since we list each element of a set only once, the range is

{19, 4, 7}

rather than

{19, 4, 17, 4}.

It's great that 4 is so eager to be a part of things, but we're not going to give him two tickets to the same show.