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Math Help - Convex set in LPP

  1. #1
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    Convex set in LPP

    Is the set X={(x1,x2)|x22>=4x1} convex or not ? How to prove it mathematically ?

    This is a problem in Linear Programming Problem (LPP). Please help
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  2. #2
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    Re: Convex set in LPP

    Hey Suvadip.

    Is it possible to use the Hessian for this system?
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  3. #3
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    Re: Convex set in LPP

    It seems to me the simplest way is just to graph it. Using x= x1, y= x2, the graph of y^2= 4x is a parabola and the set {(x, y)| y^2>= x} is the set of points outside the parabola. That would lead me to look at the points (1, 2) and (1, -2). 2^2= 4> 1 and (-2)^2> 1 so both (1, 2) and (1, -2) is in the set. But (1, 0) is NOT.
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