# Algebra 1 - 4th Edition

## Chapter 5: Functions

Some links are repeated for use with more than one lesson.

### 5.1 Relations and Functions

http://www.mathwarehouse.com/algebra/relation/math-function.php
This site explains relations and functions and has practice problems.

http://www.purplemath.com/modules/fcns.htm
This page contains a written lesson explaining the differences between relations and functions and how to tell them apart.

### 5.2 Evaluating Functions

http://www.algebralab.org/lessons/lesson.aspx?file=Algebra_FunctionsRelationsEvaluation.xml
This page contains a description of how to evaluate functions with practice problems.

http://www.sparknotes.com/testprep/books/newsat/chapter19section11.rhtml
This site explains how to evaluate functions and how to use them for different operations.

### 5.3 Operations with Functions

http://www.mathsisfun.com/sets/functions-operations.html
This site discusses and provides practice for combining functions with the four basic operations and analyzing the domain of the resulting function.

http://www.mathsisfun.com/sets/functions-composition.html
This site discusses and provides practice for using and identifying the domain of composite functions.

http://www.regentsprep.org/Regents/math/algtrig/ATP7/indexATP7.htm
This site discusses and provides practice with function composition, and finding the domain of composite functions.

### 5.4 Direct Variation

http://www.explorelearning.com/index.cfm?method=cResource.dspDetail&ResourceID=129
This page contains a gizmo that has a graph displaying direct and inverse variation.

http://hotmath.com/help/gt/genericalg1/section_9_8.html
This site contains practice problems for direct and inverse variation.

### 5.5 Nonlinear Functions

http://fym.la.asu.edu/~tturner/MAT_117_online/Graph_features/Graph_features.htm
This page describes nonlinear functions and their graphs and has graph examples.

### 5.6 Arithmetic Sequences

http://www.mathsisfun.com/algebra/sequences-series.html
This site discusses and provides practice with sequences, including some familiar sequences.

http://www.regentsprep.org/Regents/math/algtrig/ATP1a/Sequences.htm
This site discusses and provides practice with sequences.

### 5.7 Perimeter and Area as Functions

http://www.mathopenref.com/polygonregulararea.html
This site includes discussion, interactive graphics, and links (scroll down) to related topics about area and perimeter functions for regular and irregular polygons.