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.
(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