Set A contains zip codes from the US and set B contains US citizen's social security numbers. The elements of these sets can be paired in that each person has a zip code for their legal address (or domicile) and each person has a social security number.
(a) If these are written as orderes pairs of the form (Zip code, Social security number) do we have a function? why or why not?
(b) Social security number, zip code? why or why not?
for (a) i said yes because if it was to be plotted it would past the line test.
for (b) i said no because it would not pass the line test.
Does the line test have anything to do with it? Am I right? What did I do wrong?
Hint: Evey US citizen has exactly one legal address even if they own more than 1 house or live part time in one town and part time in another town (like a college student living in a door). Determining which address is your legal address can be quite tricky for some people, but it is important for tax purposes.