Results 1 to 10 of 10

Math Help - prove

  1. #1
    Newbie
    Joined
    Feb 2008
    Posts
    6

    prove

    im lookin for some help on this prove...

    Let U be a set and let A and B be subsets of U.
    Prove (A\B) compliement = A compliment Union B

    thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,605
    Thanks
    1574
    Awards
    1
    \left( {A\backslash B} \right)^c  = \left( {A \cap B^c } \right)^c
    You should be able to carry it forward and finish.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Feb 2008
    Posts
    6
    would anybody be able to help work this out? I'm new at this, and the more info that could be included, the more it would help me out. thanks, i appreciate it
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,838
    Thanks
    320
    Awards
    1
    Quote Originally Posted by rodemich View Post
    would anybody be able to help work this out? I'm new at this, and the more info that could be included, the more it would help me out. thanks, i appreciate it
    Show us what you can do with Plato's hint.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Feb 2008
    Posts
    6
    well i know to prove the equivalence, i need to prove that the statement is true both ways, right?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie
    Joined
    Feb 2008
    Posts
    6
    so i gotta prove both

    (A/B)* is a subset of A* U B

    and

    A* U B is a subset of (A/B)*
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    9,838
    Thanks
    320
    Awards
    1
    Quote Originally Posted by rodemich View Post
    well i know to prove the equivalence, i need to prove that the statement is true both ways, right?
    I don't understand. If you can show \left ( A \backslash B \right ) ^c can be transformed into \left ( A \cap B ^c \right )^c then you are done.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  8. #8
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by rodemich View Post
    so i gotta prove both

    (A/B)* is a subset of A* U B

    and

    A* U B is a subset of (A/B)*
    that's the hard way. continue from where Plato left off, and apply one of DeMorgan's laws

    (do you know DeMorgan's laws?)
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Newbie
    Joined
    Feb 2008
    Posts
    6
    im fairly familiar with De Morgans Laws, but not enough to use it on my own yet
    Follow Math Help Forum on Facebook and Google+

  10. #10
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by rodemich View Post
    im fairly familiar with De Morgans Laws, but not enough to use it on my own yet
    if X and Y are sets, what would DeMorgan's laws transform (X \cap Y)^c into?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Prove a/b and a/c then a/ (3b-7c)
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: March 23rd 2010, 05:20 PM
  2. prove,,,
    Posted in the Number Theory Forum
    Replies: 1
    Last Post: March 1st 2010, 09:02 AM
  3. Prove |w + z| <= |w| +|z|
    Posted in the Algebra Forum
    Replies: 3
    Last Post: February 28th 2010, 05:44 AM
  4. Replies: 2
    Last Post: August 28th 2009, 02:59 AM
  5. How to prove that n^2 + n + 2 is even??
    Posted in the Algebra Forum
    Replies: 3
    Last Post: November 30th 2008, 01:24 PM

Search Tags


/mathhelpforum @mathhelpforum