What does it mean for a set to be bounded?

In summary, being bounded means that the elements of a set are limited to a specific range or interval. This is determined by analyzing the values within the set, which can have a minimum and maximum value or an upper and lower bound. A set cannot be both bounded and unbounded, but it can have a combination of finite and infinite elements. The boundedness of a set can affect mathematical operations, with bounded sets resulting in values within the same bounds and unbounded sets potentially producing infinite or undefined results. It is also possible for a set to be bounded in one dimension and unbounded in another.
  • #1
royzizzle
50
0
what does it mean for a set to be bounded??

in the context of the hein-borel theorem

i mean the mathematically rigorous definition
 
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  • #2


S a subset of Rn is bounded if there exists M>0 so that for all x in S, |x|<M
 
  • #3


Another equivalent definition is that it has finite diameter, where

[tex]\mathrm{diam}(S) = \sup_{x, y \in S}(\mathrm{dist}(x, y)).[/tex]

This is applicable to any metric space (though the Heine-Borel theorem is not!).
 

1. What does it mean for a set to be bounded?

Being bounded means that there is a finite limit or range in which all the elements of the set exist. In other words, the values in a bounded set are constrained within a certain interval or region.

2. How is boundedness determined in a set?

The boundedness of a set is determined by analyzing the values within the set. If all the values fall within a specific range, then the set is bounded. This range can be defined by a minimum and maximum value, or by an upper and lower bound.

3. Can a set be both bounded and unbounded?

No, a set cannot be both bounded and unbounded. A set is either bounded or unbounded, depending on the values within it. A set can have a combination of finite and infinite elements, but it cannot have both finite and infinite boundaries.

4. How does boundedness affect mathematical operations?

The boundedness of a set can affect mathematical operations in different ways. For example, in a bounded set, the operations of addition and multiplication will always result in values that fall within the same bounds. However, in an unbounded set, the result of these operations may be infinite or undefined.

5. Can a set be bounded in one dimension and unbounded in another?

Yes, a set can be bounded in one dimension and unbounded in another. For example, a set of points on a line can be bounded in terms of their x coordinates but unbounded in terms of their y coordinates. This is known as a bounded set in one dimension and unbounded in the other.

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