A Property of set with finite measure

In summary, to show that E is the disjoint union of a finite number of measurable sets with measure at most \epsilon, one can proceed by taking a finite group of open sets containing E, taking their closures, and finding a finite number of points within each closure that form open neighborhoods with measure at most \epsilon. By taking the intersections of these sets with E and then taking differences and intersections of the sets themselves, one can ensure that the finite number of subsets are disjoint and their union is equal to E.
  • #1
ntsivanidis
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Homework Statement



If E has finite measure and [tex]\epsilon[/tex]>0, then E is the disjoint union of a finite number of measurable sets, each of which has measure at most [tex]\epsilon[/tex].

Homework Equations



The Attempt at a Solution


I proceeded by showing that by definition of measure, there is a finite group of open sets [tex]O_i[/tex] that contain E, whose union has the same measure (and contains E). By taking their closure, by compactness each has an open cover of [tex]\epsilon[/tex] neighborhoods of a finite number of points. The union of these, within each [tex]O_i[/tex] and then across all [tex]O_i[/tex], contains E.

My problem is i)to ensure the finite number of subsets are disjoint, and ii) to ensure that the union of these sets is equal to E.

Thanks!
 

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  • #2
Then why don't you take the intersections of your sets with E and then differences and intersections of the sets themselves?
 

Related to A Property of set with finite measure

1. What is a property of a set with finite measure?

A property of a set with finite measure is that it has a well-defined and finite size or capacity. This means that the set can be measured or counted, and the resulting measurement will be a finite number.

2. How is the measure of a set determined?

The measure of a set is determined by the size or extent of the set. This can be done by measuring the length, area, or volume of the set, depending on its dimensionality. The resulting measurement will be a finite number, indicating the finite measure of the set.

3. What is the difference between a set with finite measure and one with infinite measure?

A set with finite measure has a well-defined and finite size, while a set with infinite measure has an unbounded or unlimited size. This means that the measure of an infinite set cannot be determined as it does not have a specific size or capacity.

4. Can a set have both finite and infinite measure?

No, a set can only have either finite or infinite measure, but not both. If a set has an infinite measure, it cannot also have a finite measure as it would contradict the definition of infinite measure.

5. How does the property of finite measure affect the study of sets?

The property of finite measure is important in the study of sets as it allows for the precise measurement and comparison of sets. It also allows for the application of mathematical principles and formulas, making the study of sets more rigorous and well-defined.

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