Question

In your own words, explain what the domain of a relation is and give an example.

Answer 1

Domain is all possible inputs.

For example, if f(x) = sqrt(x), then x can be any non-negative real number (assuming that f(x) must be a real number). x can't be negative, because then f(x) would not be a real number

Source: http://answers.yahoo.com/question/index?qid=20101230111330AAZv5ik