Question

what is the difine of empty set(null set). =​

Answer 1

Answer:

In mathematics, the empty set is the unique set having no elements; its size or cardinality is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set, while in other theories, its existence can be deduced.

Answer 2

Answer:

A set that contains no element is called an empty set.