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What is the value of b + c if x^2 + bx + c > 0 only when x is in (-inf,2) U (8,inf)?

 Mar 9, 2022
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The domain shows this to be a dome shaped parabola with zeroes ( roots ) at 2   and 8

  the quadratic then becomes

     ( x-2)(x-8)      expand

        x^2 -10x + 16  >0              <======== take it from here

 

Here is a graph :  https://www.desmos.com/calculator/7f05zasszq

 Mar 9, 2022

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