Question 810827
vertex form: {{{y=a(x-h)^2+k}}}
h is the x value in the vertex and k is the y value in the vertex.
a is the coefficient.
the vertex form is {{{y=a(x-2)^2-4}}}
you want find a so plug in the x and y value they give you and solve for a.
{{{-1=a(3-2)^2-4}}}
{{{-1=a-4}}}
{{{3=a}}}
The vertex equation of the parabola they give you is
{{{y=3(x-2)^2-4}}}
The coefficient is 3.