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Math Help - Question about Convex sets

  1. #1
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    Question about Convex sets

    this is my problem

    Suppose that X ⊆R^n is a convex set and f:X →R is a concave function, prove that the set

    { z∈X | f(z) ≥ f(x) for all x∈X}

    is convex.

    Can someone help me? I'm clueless on this one...
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  2. #2
    CSM
    CSM is offline
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    Start by putting in your definitions... Write down what you want to prove, and what you already know.

    BTW: here is a solution

    Yahoo! Canada Answers - Prove a set is convex?
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