Results 1 to 4 of 4

Math Help - Relationship of Boundaries

  1. #1
    Member aldrincabrera's Avatar
    Joined
    Jun 2011
    From
    Dumaguete City
    Posts
    90

    Smile Relationship of Boundaries

    ,.,just wondering..

    what is the relationship of boundary(A intersection B) to boundary(A) and boundary(B)???
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Drexel28's Avatar
    Joined
    Nov 2009
    From
    Berkeley, California
    Posts
    4,563
    Thanks
    21

    Re: Relationship of Boundaries

    Quote Originally Posted by aldrincabrera View Post
    ,.,just wondering..

    what is the relationship of boundary(A intersection B) to boundary(A) and boundary(B)???
    What do you think, what does your intuition tell you? What about something like (a,b),(b,c)? What is \partial((a,b)\cap (b,c))? What about \partial(a,b)\cap\partial(b,c)?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member aldrincabrera's Avatar
    Joined
    Jun 2011
    From
    Dumaguete City
    Posts
    90

    Re: Relationship of Boundaries

    ,.,.i have this silly intuition.,.,.my intuition says that boundary(A intersection B) is a subset of boundary(A) and boundary(B),.,i know im wrong,.,.hahahah
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor FernandoRevilla's Avatar
    Joined
    Nov 2010
    From
    Madrid, Spain
    Posts
    2,162
    Thanks
    45

    Re: Relationship of Boundaries

    Quote Originally Posted by aldrincabrera View Post
    ,.,.i have this silly intuition.,.,.my intuition says that boundary(A intersection B) is a subset of boundary(A) and boundary(B),.,i know im wrong,.,.hahahah
    Yes, you are wrong . In \mathbb{R} with the usual topology choose A=[0,2],\;B=[1,3] . Then, \partial(A\cap B)=\{1,2\} and \partial (A)\cap \partial (B)=\emptyset .
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. PDE with moving boundaries
    Posted in the Differential Equations Forum
    Replies: 0
    Last Post: May 4th 2011, 09:40 AM
  2. Boundaries
    Posted in the Math Topics Forum
    Replies: 10
    Last Post: January 8th 2011, 12:27 PM
  3. Replies: 12
    Last Post: February 16th 2010, 04:41 PM
  4. Need help with the boundaries of a 3D solid
    Posted in the Calculus Forum
    Replies: 2
    Last Post: February 13th 2010, 12:46 PM
  5. Polar Boundaries.
    Posted in the Calculus Forum
    Replies: 6
    Last Post: October 20th 2009, 03:13 AM

Search Tags


/mathhelpforum @mathhelpforum