Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Can someone explain these two examples of an open set

  1. Oct 23, 2016 #1
    Screenshot below
    -Thanks
     

    Attached Files:

  2. jcsd
  3. Oct 23, 2016 #2

    FactChecker

    User Avatar
    Science Advisor
    Gold Member

    4) Apparently they have already proven that the open ball in R is an open set. That may be their original definition of an open set. They have also proven that any union of open sets is open. So all they need to do is to rewrite the original set of 4) as the union of balls.
    5) Same logic as in 4) except that the balls are in the complex plane, C.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Can someone explain these two examples of an open set
  1. Open set x open set (Replies: 6)

  2. Open set (Replies: 2)

  3. Open sets and closures (Replies: 8)

  4. Open set (Replies: 19)

Loading...