Sets

Union and Intersection

Notation • { }Ex. Set A={2,4,6,8,10,12,…}

- infinite set (never ends)Ex. Set B={2,4,6,8,10,12}

- finite set (has a certain amount)Ex. Set C={…,2,4,6,8,10,12,…}

- infinite set

Venn Diagrams• Used to visually represent sets of

data

• An organization of data using overlapping circles

• Data gathered in sets

• Sets can be made up of numbers, amounts, etc.

Using the following sets create a Venn Diagram

Number Sets

• Set A = {3,6,9,12,15}

• Set B = {2,4,6,8,10,12,14}

• Set C = {5,10,15}

Set B Set C

Set A

{3,6,9,12,15}

{2,4,6,8,10,12,14} {5,10,15}

Set B Set C

Set A

3, 9

15

10 5

6,12

2,4,8,14

Symbols • The following symbols can be used with Venn

Diagrams and Sets

- Union– Numbers that are in either or and both– Every number listed in order once

- Intersection

– Numbers that are in both

• Ø – empty set – A set with no values

Using the number sets from before find the following:

1. A B = 2. A B =

3. A C = 4. B C =

5.ABC = 6.ABC =

1.AB=

2.AB=

3.AC=

4.BC=

5.ABC=

6.ABC=

{6,12}

{2,3,4,6,8,9,10,12,14,15}

{10,15}

{2,4,5,6,8,10,12,14,15}

Ø

{2,3,4,5,6,8,9,10,12,14,15}

Key Points •Set Notations•Venn Diagrams•Union•Intersection•Empty Set