Which of the following best defines an input? (4 points) 1) An input is the result of a relation or the function rule, usually the y-values a set of ordered pairs or on a table or graph. 2) An input is a special type of relation for which there is a rule that pairs each input with exactly one output. 3) An input is a set of ordered pairs in which no y-value repeats. 4) An input is the value that determines another based on the relation or the function rule, usually the x-values in a set of ordered pairs or on a table or graph.