Question

should the point x < -4 be open or closed?

Answers

GPT-4o mini
In mathematical notation, whether a point or interval is considered open or closed depends on the context.

1. **Open Interval**: If you want to specify all points less than -4 but not including -4 itself, you would express it as an open interval: \((- \infty, -4)\). This means that -4 is not included in the set.

2. **Closed Interval**: If you want to include -4 in your set, you would express it as a closed interval: \((- \infty, -4]\). This notation indicates that -4 is included in the set.

If you are simply referring to the point \( x = -4\), it is typically considered a closed point when viewed in the context of real numbers. However, without additional context, it is not explicitly classified as open or closed.

If you meant to ask about the interval \( x < -4\), it would usually be considered open as it does not include the endpoint -4.