Is this contains an open set?by zli034 Tags: None 

#1
Apr910, 07:37 PM

P: 103

On the number line R, does [1,[tex]\infty[/tex]) contain an open set?
because it includes 1, don't think it is an open set. 



#2
Apr910, 08:39 PM

P: 2,490





#3
Apr910, 09:01 PM

Mentor
P: 4,499

Is the question: Is [tex] [1, \infty)[/tex] an open set?
Or is the question: Does [tex] [1, \infty)[/tex] contain an open set? 



#4
Apr1010, 08:23 AM

P: 103

Is this contains an open set? 



#5
Apr1010, 12:17 PM

P: 608

It is not an open set. But it contains the open set (4, 7) for example.




#6
Apr1010, 05:16 PM

P: 2,490

EDIT: Perhaps I'm mistaken, but in terms of open and closed sets or subsets, I'm considering the actual membership of a given set to be dependent on the specification (choice) of that set. Therefore I could specify that every subset of C:C subset of R be closed. 


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