Proving T(x,y) is a Metric on Compact Set

In summary, to prove that T(x,y) = something is a metric on a set that is compact, it must satisfy the three axioms of distance. Showing that something is a metric requires demonstrating that it meets the definition of a metric. However, the phrase "for which it is compact" may be misleading as metrics themselves are not compact and the compactness of the underlying space is irrelevant in determining whether or not a function is a metric.
  • #1
Bachelier
376
0
To show that some T(x,y) = something
is a metric on a set for which it is compact, we have to prove that it respects the 3 axioms of distance. right?
 
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  • #2
Is this is a serious question?
 
  • #3
Yes, to show that something is a metric, we must show that it satisfies the definition of a metric- which is just those three "axioms" you mention.

In general to show that something is "A" you must show that it satisfies the definition of "A"! I suspect that was the reason for Landau's question.

But I am concerned about that phrase "for which it is compact". The "it" there should refer to the metric you just mentioned but metrics are not "compact". And if you meant the set, whether or not a given function is a metric has nothing to do with whether or not the underlying topological space is compact.
 

1. What is a metric?

A metric is a mathematical function that measures the distance between two points in a given space. It is often used to quantify the similarity or difference between objects.

2. What is a compact set?

A compact set is a subset of a metric space that is closed and bounded. This means that it contains all of its limit points and can be contained within a finite distance.

3. How do you prove that T(x,y) is a metric on a compact set?

To prove that T(x,y) is a metric on a compact set, you need to show that it satisfies the three properties of a metric: positivity, symmetry, and the triangle inequality. You also need to show that it is well-defined on the set and has a finite range.

4. What is the importance of proving that T(x,y) is a metric on a compact set?

Proving that T(x,y) is a metric on a compact set is important because it ensures that the distance function is well-behaved and can accurately measure the similarity or difference between objects in the given space. It also allows for the use of various mathematical tools and techniques that rely on the properties of a metric.

5. What are some common examples of metrics on compact sets?

Some common examples of metrics on compact sets include the Euclidean metric, the Manhattan metric, and the Chebyshev metric. These metrics are commonly used in geometry, statistics, and other fields to measure distances between points in a given space.

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