The Discriminant Using Sliders

Topic:
Parabola
Move the a, b and c sliders and watch the graph and the value under the square root of the quadratic equation. What can we determine about the graph by analyzing the "discriminant"?
When the discriminant is positive the graph has what properties? When the discriminant is negative where is the graph located? When the discriminant is zero where is the graph located? What if the discriminant is a perfect square, what can we determine about the graph?