Role of a, h and k in y = a (x - h)^2+ k

The purpose of this applet is to illustrate how the values of a, h and k affect the parabola y = a( x - h)^2 +k. Use it as follows:

  1. Use the scroll bar to change the values of a (between -10 and 10). The opening of the parabola should change as a changes. The value of a to the left of the scroll bar should also be updated.
  2. Use the scroll bar to change the values of h and k(between -10 and 10). The position but not the shape of the parabola should change as h and k change. The value of h and k to the left of the scroll bar should also be updated.