Show that the unbounded region determined by a closed curve is doubly connected











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Show that the unbounded region determined by a closed curve is doubly connected.




I am not sure what to do here. I proved that a bounded component determined by the curve is simoly connected, so that I only have to show that the union of such bounded components are connected. But how do I show this? The below proof just assumes this but this is not immediately clear to me.



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    Do you consider a curve in $mathbb{R}^2$? What does "doubly connected" mean in that context?
    – Paul Frost
    Nov 8 at 12:41












  • @PaulFrost A doubly connected region $K$ has two components in $mathbb C - K$; for example, the unit circle has two components, one the unit disk and the other the region with infinity.
    – Cute Brownie
    Nov 15 at 18:15















up vote
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down vote

favorite













Show that the unbounded region determined by a closed curve is doubly connected.




I am not sure what to do here. I proved that a bounded component determined by the curve is simoly connected, so that I only have to show that the union of such bounded components are connected. But how do I show this? The below proof just assumes this but this is not immediately clear to me.



1










share|cite|improve this question




















  • 1




    Do you consider a curve in $mathbb{R}^2$? What does "doubly connected" mean in that context?
    – Paul Frost
    Nov 8 at 12:41












  • @PaulFrost A doubly connected region $K$ has two components in $mathbb C - K$; for example, the unit circle has two components, one the unit disk and the other the region with infinity.
    – Cute Brownie
    Nov 15 at 18:15













up vote
0
down vote

favorite









up vote
0
down vote

favorite












Show that the unbounded region determined by a closed curve is doubly connected.




I am not sure what to do here. I proved that a bounded component determined by the curve is simoly connected, so that I only have to show that the union of such bounded components are connected. But how do I show this? The below proof just assumes this but this is not immediately clear to me.



1










share|cite|improve this question
















Show that the unbounded region determined by a closed curve is doubly connected.




I am not sure what to do here. I proved that a bounded component determined by the curve is simoly connected, so that I only have to show that the union of such bounded components are connected. But how do I show this? The below proof just assumes this but this is not immediately clear to me.



1







general-topology complex-analysis






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share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 8 at 5:19

























asked Nov 8 at 4:11









Cute Brownie

947316




947316








  • 1




    Do you consider a curve in $mathbb{R}^2$? What does "doubly connected" mean in that context?
    – Paul Frost
    Nov 8 at 12:41












  • @PaulFrost A doubly connected region $K$ has two components in $mathbb C - K$; for example, the unit circle has two components, one the unit disk and the other the region with infinity.
    – Cute Brownie
    Nov 15 at 18:15














  • 1




    Do you consider a curve in $mathbb{R}^2$? What does "doubly connected" mean in that context?
    – Paul Frost
    Nov 8 at 12:41












  • @PaulFrost A doubly connected region $K$ has two components in $mathbb C - K$; for example, the unit circle has two components, one the unit disk and the other the region with infinity.
    – Cute Brownie
    Nov 15 at 18:15








1




1




Do you consider a curve in $mathbb{R}^2$? What does "doubly connected" mean in that context?
– Paul Frost
Nov 8 at 12:41






Do you consider a curve in $mathbb{R}^2$? What does "doubly connected" mean in that context?
– Paul Frost
Nov 8 at 12:41














@PaulFrost A doubly connected region $K$ has two components in $mathbb C - K$; for example, the unit circle has two components, one the unit disk and the other the region with infinity.
– Cute Brownie
Nov 15 at 18:15




@PaulFrost A doubly connected region $K$ has two components in $mathbb C - K$; for example, the unit circle has two components, one the unit disk and the other the region with infinity.
– Cute Brownie
Nov 15 at 18:15















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