Vertex Form Quadratics

Play with the values of "a", "h", and "k" to see how each affects the shape of the parabola, then try to approximate the quadratic function of famous parabolas in the real world.
1) What happens when "a" is large? What about when "a" is negative? 2) What happens to the graph when "h" is adjusted? 3) How does changing "k" affect the parabola? 4) Using the check boxes, see if you can approximate the quadratic function for the Gateway and McDonald's Arches.