1.3 Relations and Functions

Checkpoint 1 Answers

1. The domain is the set of Social Security numbers of members of your class. The rule is to assign to each Social Security number the weight of the person who owns that number.
2. The domain is the set of dates 1975, 1980, 1985, 1990, 1995, 2000. The rule is to assign to each date the y-coordinate of the corresponding point on the graph, that is, the per-capita cigatrette consumption in that year.
3. The domain is the set of all real numbers, and the rule is to square each number.
4. The domain is the set of nonnegative numbers, and the rule is to take the square root of each number in the domain.