1. Let \( A=\{1,2,3,4\} \) and \( B=\{a, c\} \). Write the following sets by listing their elements between braces: (a) \( A \times B \) (b) \( B \times B \) (c) \( \emptyset \times B \) (d) \( (A \times B) \times B \)
Upstudy AI Solution
Answer
Solution
Answered by UpStudy AI and reviewed by a Professional Tutor


Extra Insights
(a) The Cartesian product \( A \times B \) consists of all ordered pairs where the first element is from \( A \) and the second element is from \( B \). Therefore, \( A \times B = \{(1,a), (1,c), (2,a), (2,c), (3,a), (3,c), (4,a), (4,c)\} \). (b) The Cartesian product \( B \times B \) consists of all ordered pairs where both elements are from \( B \). Thus, \( B \times B = \{(a,a), (a,c), (c,a), (c,c)\} \). (c) The Cartesian product \( \emptyset \times B \) is the set of all ordered pairs where the first element is from the empty set \( \emptyset \) and the second is from \( B \). Since there are no elements to pair with, \( \emptyset \times B = \emptyset \). (d) The Cartesian product \( (A \times B) \times B \) consists of all ordered pairs where the first element is from \( A \times B \) and the second is from \( B \). Therefore, \( (A \times B) \times B = \{((1,a),a), ((1,a),c), ((1,c),a), ((1,c),c), ((2,a),a), ((2,a),c), ((2,c),a), ((2,c),c), ((3,a),a), ((3,a),c), ((3,c),a), ((3,c),c), ((4,a),a), ((4,a),c), ((4,c),a), ((4,c),c)\} \).