Sets and Set Notation Flashcards
Define the meaning of the word “set”.
A set is a well-defined collection of distinct items or objects.
Which of the following is a set?
- Collection of animals weighing at least 300 kg
- Collection of large animals
1
Which of the following is a set?
- Collection of rich people
- Collection of billionaires
2
What are the objects or items in the set called?
elements
What does “…” mean and when do you use it?
It is an ellipsis. There are two uses, one is to indicate infinity, the other is to save writing long lists.
What does “∈” mean?
It means that an object is an element of the set.
What does “∉” mean?
It means that the term is not an element of the set.
Given set Y= {1, 3, 5, …, 55, 57, 59}
20∈/∉ Y
∉
Define what A⊆B means.
It means that set A is a subset of set B because all the elements of set A are in set B.
Define what A⊂B means.
It means that set A is a proper subset of B because set A is a subset of set B and B has at least 1 element that is not in A.
What is the formula to get the number of subsets in a set?
2^n
What is the formula to get the number of proper subsets in a set?
2^n-1
What is a universal set?
Denoted by U, is the set of all possible elements of any set used in the problem.
Define an empty set or null set.
It is a set with no elements.
True or False.
An empty set is always a subset of any set.
True
Differentiate equal sets from equivalent sets.
Equal sets are sets that contain exactly the same elements while equivalent sets are sets that contain exactly the same number of elements.
What is the sign for equivalent sets?
≈
Can a set contain repeated elements?
No.
Differentiate finite sets from infinite sets.
A finite sets is one in which it is possible to count all the elements of the set. An infinite set is one in which it is not possible to list and count all the elements of the set.
What is the symbol for cardinality?
I I
What is a verbal description?
Describing a set in words
What is the roster/tabular method?
Listing each element of the set inside braces
What is the rule method/set builder notation?
Listing the rules that determine whether an object is an element of the set rather than actual elements
How do you read xIx?
X such that x
