A parabola’s vertex form looks like $f(x) = a(x-h)^2+k$. The following is the graph of a parabola. If you would like to enlarge the graph or make numbers and letters easier to read, you may click on it to open it in a new window. You may then enlarge that window with your mouse. To further enlarge the image, use your browser’s zoom capabilities. On a PC this is usually ctrl shift + (and zooming out is ctrl -). On an Apple computer this is usually apple shift + (and zooming out is apple -). Based on the graph, write this parabola’s formula in vertex form.