Examine the following lists below and group the lists into three:

-2,-3,-4,-5,-62,7,8,11,193,6,9,12,151,3,9,27,81

0,1.1,4,5,7.7

What is an arithmetic sequence?

A sequence in which

each term is found by

ADDING the same

number to the previous

term.

4, 8, 12 , 16, 20………….. +4 +4+4 +4

What is the common difference?

The difference between

each number. This

determines what is added to

each previous number to

obtain the next number.

4, 8, 12, 16, 20…………..4 is the common difference

What is a geometric sequence?

A sequence in which

each term can be found

by multiplying the

previous term by the

same number.

3, 9, 27 , 81, 243………….. x3 x3x3 x3

What is the common ratio?

The number used to multiply

by each previous number to

obtain the next number.

2, 8, 32, 128, 512…………..4 is the common ratio

Let’s

Practice!

Is this an arithmetic or geometric sequence?

10, 15, 20, 25, 30……

Arithmetic Sequence

+5

5 is the common difference

Is this an arithmetic or geometric sequence?

2, 12, 72, 432, 2,592……

Geometric Sequence

x6

6 is the common ratio

What is the next term in this sequence?

5, 20, 80, 320 , _____

1,280

x4 x4 x4 x4

What is the next term in this sequence?

5, -1, -7 -13 , _____

-19

-6 -6 -6 -6

What is the next term in this sequence?

-3, 6, -12, 24 , _____

-48

X-2 X-2 X-2 X-2

What is the next term in this sequence?

-400,-380,-360,-340 , ____

-320

+20 +20 +20 +20

What is the next term in this sequence?

100, 75, 50 , 25____

0

-25 -25 -25 -25

What is the next term in this sequence?

12, -48, 192 , -768____

3,072

x-4 x-4 x-4x-4