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Math Help - Sets

  1. #1
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    Exclamation Sets

    I'm not real sure about a defn. in this problem and need some clarification.
    The problem reads..
    "The universe is all Real #'s. Let A be the closed interval [0,2] and let B be the closed interval [-1,1]. Find A\B, etc etc."

    My question is this: By closed interval, does this mean (for A) that the set is all real #'s between (and including) zero and two? And if not, what does it mean?

    Thanx!
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  2. #2
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    [ denotes closed, as in it contains the number, in this case 0 and 2
    ( denotes open, contains everything up to the number but not the number itself.
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  3. #3
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    Question

    Quote Originally Posted by terr13 View Post
    [ denotes closed, as in it contains the number, in this case 0 and 2
    ( denotes open, contains everything up to the number but not the number itself.
    So...Just as I thought....The set contains every real # between and including 0 & 2 for set A; and -1 & 1 for set B...correct? Or just A={0,2} and B={-1,1}....doesn't seem right...
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  4. #4
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    All reals in between and including.
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  5. #5
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    Thumbs up

    Quote Originally Posted by terr13 View Post
    All reals in between and including.

    Just as I thought..Thank You!
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