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Homework Help: Rational numbers - bounded subset with no least upper bound

  1. Jan 9, 2012 #1
    1. The problem statement, all variables and given/known data

    Give an example of a bounded subset of Q which has no least upper
    bound in Q. Explain why your answer has this property.

    2. Relevant equations

    3. The attempt at a solution

    [1/8, 1/4, 3/8, 1/2, 5/8, 3/4.....infinity]
    is this correct?
  2. jcsd
  3. Jan 9, 2012 #2


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    Science Advisor
    Homework Helper
    Gold Member

    No. Hint: What kind of numbers are missing from Q? Find a bounded set that has one of them for its lub.
  4. Jan 9, 2012 #3


    Staff: Mentor

    Your set appears to be integer multiples of 1/8. This set is not bounded, so doesn't qualify as an example in this problem.
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