## Precalculus (6th Edition)

A function $f$ is a one-to-one function if different values of the domain correspond to different values of the range. ($a\neq b$ implies $f(a)\neq f(b)$) ----------------- The domain of f contains five values (states). Here, we have two different states from the domain, Maine and New Hampshire having the SAME value (2) from the range so the function is not one-to-one