1. ALGEBRA II HONORS/GIFTED @
ALGEBRA II HONORS/GIFTED - SETS : THE COMPLEMENT OF A SET and CROSS PRODUCTS
ALGEBRA II HONORS/GIFTED @
SETS : THE COMPLEMENT OF A SET and CROSS PRODUCTS

2. U
U = {students at Chiles}
A = {students in this class} A
1) What can you say about the region inside U, but not in set A?
COMPLEMENT : of a set are the elements in U, but not in the specified set . Complements are noted using the symbols A’ or

3. ROSTER METHOD : a way to write the elements of a set by listing all of the elements.
RULE METHOD : a way to write the elements of a
set by definition.
Let : U = {1, 2, 3, 4, …, 20} J = {2, 4, 6, 8, …, 20}
K = {2, 3, 5, 7, 11, 13, 17, 19} L = {1, 3, 9, 11}
2) Each set above is described using the roster method. Describe the same sets using the rule method.
3) Find the complement of sets J, K, and L.
4) Draw a Venn Diagram of sets U, J, K, and L.

4. SUBSET : if all of the elements in set A are also in set B.
Explain why… 5)
6) A set is a subset of itself. 7) U A B

5. 9) Name all subsets of {r, a, t}.
ALGEBRA II HONORS/GIFTED - SETS : THE COMPLEMENT OF A SET and CROSS PRODUCTS
8) If S = {students in this class}, name some subsets of S. Name a set which is not a subset of S.
9) Name all subsets of {r, a, t}.

6. If A = {1, 2} and B = {a, b, c}, then A x B =
{(1, a), (1, b), (1, c), (2, a), (2, b), (2, c)}
This is known as a CROSS PRODUCT. What is the cross product of two sets?
If A and B are two sets, the cross product of A and B, written A×B, is the set of all pairs wherein the first element is a member of the set A and the second element is a member of the set B.
10) So, what is B x A?

7. C = {gobbling, gobbled, goblins} and D = {gargoyles, gobbling}.
11) Find C x D if
C = {gobbling, gobbled, goblins}
and
D = {gargoyles, gobbling}.
C x D = {(gobbling, gargoyles), (gobbling, gobbling), (gobbled, gargoyles), (gobbled, gobbling), (goblins, gargoyles), (goblins, gobbling)}