Question

Which notation description is correct? Select all that apply.

When there are closed inequalities, you use parentheses "()" since they don't include the number next to them.
When there are open inequalities, you use parentheses "()" since they don't include the number next to them.

Answer 1

In interval notation, open inequalities, which do not include the boundary number, use parentheses (), while closed inequalities, which include the boundary number, use brackets [].

Step-by-step explanation:

The correct notation for intervals in mathematics uses parentheses () and brackets [], but not in the way described in the question. When dealing with closed inequalities, which include the number they are next to, brackets [] are used.

For open inequalities, which do not include the adjacent number, parentheses () are employed. For example, x > 3 is an open inequality and would be written as (3, ∞), while x ≥ 3 is a closed inequality and would be written as [3, ∞). Remember, the use of parentheses and brackets in inequalities is to denote whether the endpoints are included or not in an interval.

When there are closed inequalities, parentheses () are used since they don't include the number next to them. When there are open inequalities, parentheses () are also used since they don't include the number next to them.