Question

What are the coordinates of the vertex of f(x)=2x^2+4x+9

Answer 1

`f(x)=2x^2+4x+9 \\ a=2 \\ b=4`

The coordinates of the vertex of a parabola are (h,k) where:

`h=(-b)/(2a)=(-4)/(2 * 2)=(-4)/(4)=-1 \\ \\ k=f(h)=f(-1)=2 * (-1)^2+4 * (-1)+9=2 -4+9=7`

The coordinates of the vertex are (-1,7).