algebra
posted by kara on .
Find the domain and range of the relation, and state whether or not the relation is a function.
{(3, 9), (3, 10), (3, 11), (3, 12)}

The domain is the set of all mapped x values, which is {3}.
The range is the set of all y values that an x maps to, which is {9, 10, 11, 12}.
Because multiple x values map to different y values, the relation is not a function.