A quadratic of the form $-2x^2 + bx + c$ has roots of $x = 3 + \sqrt{5}$ and $x = 3 - \sqrt{5}.$ The graph of $y = -2x^2 + bx + c$ is a parabola. Find the vertex of this parabola.
+37146 y=(x-3+sqrt5)(x-3-sqrt5) multiply this out :
y=x^2 -3x-sqrt5x - 3x +9+3sqrt5+ sqrt5x-3sqrt5 -5 simplify
y=x^2 -6x +4 multiply by -2
y = -2x^2+12x-8
x value of vertex = - b/2a use this value of x in the equation to find the y value of the vertex
