Is it a Function? Teacher Twins©2014

Warm Up D= {2,3,5} R= {3,4,6} D= {-2,-3,4} R= {-6,0,3,5}

Is it a Function?

A set of ordered pairs is called a relation. A function is a set of ordered pairs where each input or domain value, has exactly one output or range value. A set of ordered pairs is called a relation.

Ex 1: Function- It has one output for each input.

Ex 2: Not a Function- The input of 1 has two different outputs.

Ex 3: Is the relation a function ? It passes the vertical line test so this is a function.

No, it does not pass the vertical line test. Ex 4: Is the relation a function? No, it does not pass the vertical line test.

Yes, it passes the vertical line test. Ex 5: Is the relation a function? Yes, it passes the vertical line test.

Practice Is it a function? 1. 2. yes yes

Closure How can you tell if a relation is a function when you have a set of ordered pairs? When you have a graph?