What does it mean for a set to be "closed"?

An operation performed on members of that set will result in a member of the same set.

The set has a finite number of members, as opposed to being infinitely large.

An expression belonging to a closed set cannot be used to create an expression that is not of that set.

Members of a closed set cannot be added, subtracted, multiplied, or divided.

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
2 months ago

The term "closed" in mathematics refers to specific properties of a set with respect to certain operations. To clarify, here is what "closed" typically means in different contexts:

1. **Closed under an operation**: A set is said to be closed under a particular operation (like addition, multiplication, etc.) if performing that operation on any members of the set always results in a member that is also within the same set. For example, the set of even integers is closed under addition because the sum of any two even integers is also an even integer.

2. **Not related to finiteness**: Being closed doesn't imply that a set has a finite number of members. A set can be infinitely large and still be closed under an operation.

3. **Expressions and closed sets**: This part refers more to the rules of manipulating expressions within a set. If you perform an operation on elements of a closed set, the result should still belong to that set for it to be considered closed.

4. **Operations allowed**: Members of a closed set can indeed be added, subtracted, multiplied, or divided, depending on the operation under consideration and the context of what the set is. The crucial point is that performing these operations results in elements that remain within the same set.

In summary, the correct definition of a closed set, particularly in terms of operations, is that "An operation performed on members of that set will result in a member of the same set."

anonymous anonymous answered
2 months ago

so what is the answer?

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
2 months ago

The proper definition of a set being "closed" is:

**An operation performed on members of that set will result in a member of the same set.**

This means that if you take any elements from the set and apply a particular operation (like addition, for example), the result will also be an element of that same set, which is the essence of closure in mathematics.