- Vertex Form: y = a(x - h)^2 + k, with (h,k) as the vertex.
So firstly, plug the vertex into the vertex form: 
Next, we first need to solve for a. Plug (0,-6) into the equation to solve for a as such:

<u>Now we know that our equation is y = 3(x - 1)^2 - 9.</u>
Now to solve for the zeros (x-intercepts). Set y to 0 and add 9 to both sides of the equation: 
Next, divide both sides by 3: 
Next, square root both sides: 
Next, add 1 to both sides: 
<u>Your x-intercepts are (-0.73,0) and (2.73,0), or B.</u>