## Glossary: Module 3

all informal definitions are based on

my own experience and knowledge

### Term*: Arithmetic Sequence*

* Informal Definition:*

A sequence made by adding or subtracting

the same number each time

*Formal Definition:*

An arithmetic sequence goes from one term to the next

by always adding (or subtracting) the same value

Definition from: http://www.purplemath.com/modules/series3.htm

*Example of Arithmetic Sequence:*

Example from: http://www.virtualnerd.com

### Term*: Geometric Sequence*

* Informal Definition:*

A sequence made by multiplying or dividing by the

same number each time

*Formal Definition*:

A geometric sequence goes from one term to the next

by always multiplying (or dividing) by the same value

Definition from: http://www.purplemath.com/modules/series3.htm

*Example of Geometric Sequence:*

Example from: http://www.virtualnerd.com

### Term*: Common Difference*

* Informal Definition:*

The number you add or subtract to get to the next

number in an arithmetic sequence

*Formal Definition*:

The number added (or subtracted) at each stage of an

arithmetic sequence

Definition from: http://www.purplemath.com/modules/series3.htm

*Example of Common Difference:*

Example from: http://www.virtualnerd.com

### Term*: Common Ratio*

* Informal Definition*: The number you multiply or divide each

term by to get to the next term in a geometric sequence

*Formal Definition*: The number multiplied (or divided) at each

stage of a geometric sequence

Definition from: http://www.purplemath.com/modules/series3.htm

*Example of Common Ratio:*

Example from: http://www.mathplanet.com

### Term*: Function*

* Informal Definition:*

A special kind of relationship between numbers

*Formal Definition:*

A special relationship between values. Each of its input

values gives back exactly one output value.

Definition from: http://www.Mathisfun.com

*Example of Function:*

Example from: http://www.virtualnerd.com