A quadratic of the form -2x^2 + bx + c has roots of x = 3 + sqrt(13) and x = 3 - sqrt(13). The graph of y = -2x^2 + bx + c is a parabola. Find the vertex of this parabola.
VERY similar question...you should be able to apply to this question....
https://web2.0calc.com/questions/plz-help-asap-ty#r1