Chapter 3: Functions and Graphs 3.1: Functions. Essential Question: How are functions different from relations that are not functions?. 3.1: Functions. A function consists of: A set of inputs, called the domain A rule by which each input determines one and only one output
Essential Question: How are functions different from relations that are not functions?
Because the input 1 is associated to two different outputs (as is the input 3), this relation is not a function
Because each output determines exactly one output, this is a function. The fact that 1, 3 & 9 all output 5 is allowed.