Path-Connected Sets and Their Closures: A Counterexample?

In summary, the conversation discusses the closure of a path-connected set and whether it remains path-connected. The example of the Topologist's Sine Curve is used, but it is noted that this is not a counterexample as the set can be expressed as the image of a path-connected space under a continuous function. Therefore, the claim still stands.
  • #1
Bashyboy
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5

Homework Statement


I am trying to determine whether the closure of a path-connected set is path-connected.

Homework Equations

The Attempt at a Solution


Let ##S = \{(x, \sin(1/x) ~|~ x \in (0,1] \}##. Then the the closure of ##S## is the Topologist's Sine Curve, which is known not to be path-connected. However, recalling that the image of a path-connected space under a continuous function is path-connected, and defining ##g : (0,1] \rightarrow \mathbb{R}## as ##g(x) = (x, \sin (1/x))##, we see that ##S = g((0,1])## must be a path-connected space.

My question is, would this constitute a counterexample to the claim, or have I made some error?
 
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  • #2
there is no error I guess
 

1. What is the definition of closure of a path-connected set?

The closure of a path-connected set is the set of all points that can be reached by continuously moving along any path within the set.

2. How is the closure of a path-connected set different from the closure of a general set?

The closure of a path-connected set includes all points that can be reached by a continuous path, while the closure of a general set includes all points that can be reached by any sequence of points within the set.

3. Can a path-connected set have multiple closures?

No, a path-connected set can only have one closure. This is because the closure is defined as the union of the set and all its limit points, and a path-connected set can only have one limit point for any given point within the set.

4. How does the closure of a path-connected set relate to connectedness?

A path-connected set that is also closed is considered to be connected. This is because a path-connected set is always connected, and a closed set contains all its limit points, thus preventing any gaps or breaks in the path within the set.

5. Is the closure of a path-connected set always a closed set?

Yes, the closure of a path-connected set is always a closed set. This is because the closure includes all the limit points of the set, meaning that any convergent sequence within the set will have its limit also within the set.

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