1. Mathematics Presenter Name : Mr. Pramote Phothisai Topic : Sets Subtopic : Union of sets

2. Objective 1. Explain meaning of the Union of sets. 2. Find the Union of two sets.

3. elements denoted diagram covers Union both represents region same Interesting Words

4. Phrases referring to what we will talk about The union of two sets Is the set of all elements The same elements of sets The Venn diagram That belongs to

5. Given the set What is the elements of set A? A = { 2, 5, 8, 9, 11 } and B = { 3, 5, 7, 8, 10 } Elements of set A are What is the elements of set B? Elements of set B are 2, 5, 8, 9, 11 3, 5, 7, 8, 10

6. Set A What are the same elements of sets A and B? = { 2, 5, 8, 9, 11 } and B = { 3, 5, 7, 8, 10 } The same elements of sets A and B are 5, 8

7. The union of two sets, A and B, denoted by Union of sets is the set of all elements A  BA  B that belongs to A or B or both.

8. Example 1 (a) Find A  B Let A = { 1, 3, 4, 9, 11 } and B = { 9, 11, 13 } Solution (b) n(A  B) = (a) A  B = { 1, 3,4,9,11, 13 } 6 (b) Find n(A  B)

9. Example 2 (a) Find P  Q Let P = {1, 3, 6, 8} and Q = {2, 4, 6, 8, 10} Solution (b) n(P  Q ) = (a) P  Q = { 1, 2,3,4,6,8, 10 } 7 (b) Find n(P  Q)

10. The colored region in the Venn diagram below represents A  B. It covers both the regions representing A and B. A  B = { x : x  A or x  B }

11. Try It ! (a) Find M  N Let M = {a, b, d, e} and N = {d, e, k} ? ? ? (b) Find n(M  N)

12. Let M = {a, b, d, e} and N = {d, e, k} Solution M  N = n(M  N) = {a, b, d, e, k} 5

13. OK. That’s it for today. See you next time. Thank you for your attention