1. Sets 2
2nd Year Maths

2. NAME THE FOLLOWING SYMBOLS
Revision of Symbols
NAME THE FOLLOWING SYMBOLS

3. WE JOIN SET A AND SET B TOGETHER TO MAKE A NEW SET
UNION
A U B
WE JOIN SET A AND SET B TOGETHER TO MAKE A NEW SET

4. THE ELEMENTS THAT ARE COMMON TO BOTH SET A & SET B
INTERSECTION
A ∩ B
THE ELEMENTS THAT ARE COMMON TO BOTH SET A & SET B

5. THE NUMBER 5 IS AN ELEMENT IN THE SET B∈
5 ∈ B
THE NUMBER 5 IS AN ELEMENT IN THE SET B

6. THE NUMBER THREE IS NOT AN ELEMENT IN THE SET B∉
3 ∉ B
THE NUMBER THREE IS NOT AN ELEMENT IN THE SET B

7. A NULL SET IS A SET WITH NO ELEMENTS
THE NULL SET ∅
A NULL SET IS A SET WITH NO ELEMENTS

8. SUBSET ⊂
IF A {1, 2, 3, 4, 5, 6, 7, 8} AND B {2, 4, 6} THEN B ⊂ A

9. EVERYTHING THAT IS OUTSIDE OF THE SET A
COMPLEMENT OF A SET A`
EVERYTHING THAT IS OUTSIDE OF THE SET A

10. THE NUMBER OF ELEMENTS IN A SET
CARDINAL NUMBER #
THE NUMBER OF ELEMENTS IN A SET

11. SET DIFFERENCE
A {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} B {1, 3, 5, 7, 9} We want to find all the elements in A which are not in B This is written A/B...which reads A less B To find this we remove the elements in B out of the set A A/B = {2, 4, 6, 8, 10}

12. QUESTIONS
U {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
A {1, 3, 5, 7, 9, 11, 13}
B {1, 5, 7, 10, 12}
Find:
A/B
B/A
U/A U B
U/A
U/B