Basic topology (differing metric spaces in R^2)

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SUMMARY

The discussion focuses on the properties of metric spaces defined by the metrics d1 and d2 on R^2, specifically addressing the relationship between limit points under these metrics. It establishes that (R^2, d1) and (R^2, d2) are indeed metric spaces, as they consist of a set paired with a metric. The key conclusion is that if a point (x1, x2) is a limit point of a subset under one metric, it is also a limit point under the other metric, emphasizing the interconnectedness of these definitions in topology.

PREREQUISITES
  • Understanding of metric spaces and their definitions
  • Familiarity with limit points in topology
  • Knowledge of the metrics d1 and d2, specifically the Manhattan and Euclidean distances
  • Basic concepts of neighborhoods in a topological context
NEXT STEPS
  • Study the properties of limit points in metric spaces
  • Explore the differences between various metrics, such as d1 and d2
  • Learn about open and closed sets in topology
  • Investigate the concept of convergence in different metric spaces
USEFUL FOR

Students and educators in mathematics, particularly those studying topology, metric spaces, and analysis, will benefit from this discussion.

mjkato
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Got it, thank you
 
Last edited:
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mjkato said:

Homework Statement


Let d1(x,y) = |x1 − y1| + |x2 − y2| and d2(x,y) = ((x1 − y1)^2+(x2 − y2)^2)^(1/2) be metric spaces on R^2.
d1 and d2 aren't metric spaces - they are metrics.

(R2, d1) is a metric space, and so is (R2, d1). In other words, a metric space consists of a set (such as R2) together with a metric (or measure).
mjkato said:
Prove that if a point (x1,x2) is a limit point of a subset under one metric, it is a limit point in the other.


Homework Equations





The Attempt at a Solution



I'm mostly lost here- I know a limit point contains atleast one point from the set in every neighborhood, but can't figure out how to translate that into a proof of this.
How do you describe a neighborhood?
 

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