How do I use vertex form to write the equation of a parabola on a graph? Thanks :)?

Determine if the parabola is horizontal or vertical.
If it opens upwards or downwards, the parabola is vertical and its equation has the form
     y = a(x-h)² + k

If it opens to the left or to the right, the parabola is horizontal and its equation has the form
     x = a(y-k)² + h

Find the vertex of the parabola and identify its x- and y-coordinates.
h = the x-coordinate of the vertex
k = the y-coordinate of the vertex

Find a point on the parabola (not the vertex) and identify its x- and y-coordinates. Plug the value of x, y, h, and k into the equation, then solve for a.