Algebra II: Modeling and Functions

Geometry

Functions are processes that take some input and produce some output, where every valid input produces only one specific output.

If inputs are on the horizontal $x$ -axis and outputs are on the vertical $y$ -axis on the graphs below, how many of them are functions?

Only 1 is a function Exactly 2 are functions Exactly 3 are functions All of them are functions None of them are functions