Search 7,000+ topics

Cardinality of a Set

Read this topic

Explanations 2

The cardinality of a set is the number of elements in the set. It gives us a way to describe whether two sets are the same size. For a set SSS, we write the cardinality as ∣S∣|S…
By Matt Superdock, Po-Shen Loh, Harrison Grodin
The "cardinality" of a set measures the number of "unique things" in it. We say that the cardinality of {1,5,4,1,3}\{1, 5, 4, 1, 3\}{1,5,4,1,3} is 444. Sometimes there are lots …
By Bill Cooperman

Problems 1

How do the cardinalities of the sets A = {1, 2, 3, 4, 5, ...} (the set of natural numbers) and B = {1, 4, 9, 16, 25, ...} (the set of perfect squares) compare?