Home/Eighth Grade Math/Week 19: Functions/Lesson 1

Identify Functions

A relation is a function when each input has exactly one output.

Lesson 1

Concept

Function test: - no x-value can map to two different y-values. Examples: - {(1,3),(2,5),(3,7)} is a function. - {(2,4),(2,9)} is NOT a function (x=2 has two outputs). Graph test: - vertical line test: if any vertical line hits graph twice, it is not a function.

Try it

Practice: Identify Functions.