Math Investigations Name: ________________________________ Date: ______________ Block: _________ 2.2: Venn Diagrams and Subsets (Part 1) Objectives: 1. To use Venn diagrams to depict set relationships 2. To determine whether one set is a subset of another 3. To understand the difference between a subset and a proper subset 4. To determine the number of subsets of a given set VENN DIAGRAMS & THE COMPLEMENT OF A SET Key Terms: ~ Universal Set: _____________________________________________________________________________________ _________________________________________________________________________________________________________ ~ The Complement of a Set For any set A within a universal set U, the complement of A, written as A’, is the set of elements of U that are not elements of A. ~ Venn Diagrams: U=_____________________________________________________ A=_____________________________________________________ A’=____________________________________________________ Example 1: Finding Complements Let U (Universal Set) = {a, b, c, d, e, f, g, h} M = {a, b, e, f} and (a) Find the set M’ Quick Check 1: Let U = {5, 10, 15, 20, 25, 30, 35, 40} (a) Find the set P’ N = {b, d, e, g, h} (b) Find the set N’ K = {10, 20, 30, 40} and (b) Find the set K’ P = {15, 5, 35} Consider the compliment of the Universal Set, U’. The set U’ is found by selecting all the elements of U that do not belong to U. *** There are no such elements, so there can be no elements in the set U’. Therefore U’ = ____________ SUBETS OF A SET Suppose that we are given universal set U = {1, 2, 3, 4, 5}, while A = {1, 2, 3}. ~ Every element of set A is also an element of the universal set U. Therefore, set A is a SUBSET of U _______________ If “A is not a subset of U” ________________ Example 2: Determining If One Set Is a Subset of Another Write ⊆ or ⊈ in each blank to make a true statement. (a) {3, 4, 5, 6} _______ {3, 4, 5, 6, 8} (b) {a, d, m} _______ {a, d, m, v, z} (c) {5, 6, 7, 8} _______ {6, 5, 8, 7} Quick Check 2: Write ⊆ or ⊈ in each blank to make a true statement. (a) {x, y, z} _______ {a, b, y, z} (c) {2, 32} _______ {2, 4, 8, 16, 32, 64} Complete textbook pg. 58 #5 – 12 below (b) {1, 2, 6} _______ {2, 4, 6, 8} Math Investigations 2.2: Venn Diagrams and Subsets (Part 2) Name: ________________________________ Date: ______________ Block: _________ Objectives: 1. To use Venn diagrams to depict set relationships 2. To determine whether one set is a subset of another 3. To understand the difference between a subset and a proper subset 4. To determine the number of subsets of a given set PROPER SUBSETS Suppose that we are given the following sets. B = {5, 6, 7, 8} and A = {6, 7} A is a subset of B, but A is not all of B. There is at least one element in B that is not in A. In this case A would be called a PROPER SUBSET of B _______________________ In summary, Set A is a proper subset of set B if 𝐴 ⊆ 𝐵 and 𝐴 ≠ 𝐵; written 𝐴 ⊂ 𝐵. Example 3: Determining Subsets and Proper Subsets Decide whether ⊂, ⊆, or both could be placed in each blank to make a true statement. (a) {5, 6, 7} ________ {5, 6, 7, 8} (b) {a, b, c} ________ {a, b, c} Quick Check 3: Determining Subsets and Proper Subsets Decide whether ⊂, ⊆, or both could be placed in each blank to make a true statement. (a) {x, y, z} ________ {z, y, x} (b) {3, 6} ________ {-9, -6, -3, 3, 6, 9} (c) {2, 3, 4} _______ {5, 6, 7} Complete pg. 58 #13 – 20 below *** Every set (except ∅) has at least two subsets, _______________________________________________ Example 4: Listing All Subsets of a Set Find all possible subsets of each set. (a) {7, 8} (b) {a, b, c} Quick Check 4: Listing All Subsets of a Set Find all possible subsets of each set. (a) {blue, white} (b) {5, 10, 15} COUNTING SUBSETS Formulas: Finding Number of Subsets _______________________ Finding Number of Proper Subsets _____________________________ Example 5: Finding the Number of Subsets and Proper Subsets Find the number of Subsets and Proper Subsets for each set. (a) {3, 4, 5, 6, 7} (b) {x | x is an even integer between -7 and 9} Quick Check 5: Finding the Number of Subsets and Proper Subsets Find the number of Subsets and Proper Subsets for each set. (a) {x | x is a positive whole number between 2 and 12, inclusive} (b) {1, 2, 3, 4, 5, 9, 12, 14} Complete pg. 59 #37 – 40 below