4.6 Sequences and Series

4.6 Sequences and Series

An Arithmetic sequence is an ordered list of numbers where you add the same number.

example 5, 10, 15, 20, ... a_n

5 is first position

10 is second position

n is nth position

Example 1. Write the next three terms.

First term is 2

Common difference is 5

• 7

• 12

• 15

Example 2. Write the next three terms.

First term is 10

Common difference is -2

• 8

• 6

• 4

Fill in the Blank

What are the next three numbers of the sequence.

First term is 8

common difference is 4

Answer like this 5 10 15

put a space between numbers

Fill in the Blank

What are the next three numbers of the sequence.

First term is 14

common difference is -3

Answer like this 5 10 15

put a space between numbers

Find the common difference of

13, 18, 23, 28, ....

• 5

• we add five

Find the common difference of

50, 40, 30, 20, ....

• -10

• subtract 10

• need negative / subtraction sign

Fill in the Blank

Find the common difference.

25, 50, 75, 100, ...

Fill in the Blank

Find the common difference.

9, 6, 3, 0, ...

Write the next 3 numbers of the sequence.

14, 16, 18, 20, ...

• we add 2

• 22

• 24

• 26

Write the next 3 numbers of the sequence.

32, 27, 22, 17, ...

• we subtract 5

• 12

• 7

• 2

Fill in the Blank

What are the next 3 numbers of the sequence?

1, 12, 23, 34, ...

Put a space between numbers

ex. 10 20 30

Fill in the Blank

What are the next 3 numbers of the sequence?

31, 28, 25, 22, ...

Put a space between numbers

ex. 10 20 30

Arithemetic means add or subtract.

Cannot multiply or divide or be random.

Multiple Choice

Is it a sequence?

2, 4, 8, 16

• Yes

• No

Multiple Choice

Is it a sequence?

125, 25, 5, 1, ...

• Yes

• No

Multiple Choice

Is it a sequence?

1, 2, 4, 7, ....

• Yes

• No

Graph the sequence 1, 3, 5, 7

x is the position

y is the number given.

1, 1

2, 3

3, 5

4, 7