R00505 Functions and Relations



External Links





Functions Overview was difficult because it carried the whole volume of Grade 11 with it. Here is an easy lecture. 

Relations define a relationship between input variables and output variables. For and relation to be called a function there can be only one output variable - y for every input variable -x

There are two types of functions

One - to - One

Many - to  - One

We use a Vertical Line test to test that the graph only touches the vertical line once - a function. More than once - not a function

We use the  Horizontal Line Test to test that the graph only touches the horizontal line once - a one-to-one function. More than once -  a many-to-one function

You must be able to identify the Domain and Range of each function or relation



External Links


Functions and Relations      

The Maths Page



Revision Discovering Equations    


Functions and Relations   

Exam Solutions.....      Functions and Relations

Varsity Tutors  
Maths is Fun Functions
Wolfram Mathworld  
FreeMathHelp What are Functions 
Purple Math Functions and Relations

Meta Calculator

App for plotting graphs                                  






Beyond the Grade 12  Syllabus - only advanced students should follow

 The Maths Page Rational Functions
Wikipedia      Function Composition           




Do the exercises on paper BEFORE looking at the answers




Functions Part 1 - Test  

Functions Part 2 - Test  


That Quizz      Domains and Range       
That Quizz      Functions and Relations   
That Quizz      Functions, Domain and Range     
Mathopolis Functions