North Carolina Standard Course of Study
Define, evaluate, and compare functions.
NC.8.F.1. Understand that a function is a rule that assigns to each input exactly one output.
NC.8.F.1.a. Recognize functions when graphed as the set of ordered pairs consisting of an input and exactly one corresponding output.
NC.8.F.1.b. Recognize functions given a table of values or a set of ordered pairs.