3. For the following, state the domain, range, and state whether the relation is a function. If it is not a function explain why.

{(3,2), (4,5), (8,5), (-3,2)}
{(4,5), (2,3), (-2,4), (9,3)}
{3,2), (5,10), (20, 4), (3, 8)}
.

The same x cannot map to different y values. So, with pairs (x,y) as long as all the x's are different, it's a function.