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A quadratic of the form -2x^2 + bx + c has roots of x = 3 + sqrt(11) and x = 3 - sqrt(11). The graph of y = -2x^2 + bx + c is a parabola. Find the vertex of this parabola.

 Oct 17, 2020
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(x-3+sqrt3)(x-3-sqrt3) =   x^2 -6x -2

multiply thru bu -2

-2x^2 + 12x + 4 = 0        vertex   ''x'' = - b/2a = 3  (right between the roots)

    use this value of 'x' in the equation to calculate ''y'' of the vertex

 Oct 17, 2020

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