1. Give the quadratic relation y=-2x^2+8x+42, find the vertex of the parabola.
y=-2(x^2-4x +4)+42-8 for completion of squares
y=-2(x-2)^2+34
it looks like x=2 is the symettry, so x =2 is the x coordinate for the vertex, use the original equation to find y when x=2