A.SSE.1 Quadratic using vertex, focus and directrix

A.SSE.1 This applet is designed to help you discover the key features of a parabola: y-intercept, slope, vertex, focus, and directrix. By making changes to the slope and y-intercept, you can see how the equation, focus and directrix change and their relationships. Then when given only the focus, vertex or directrix, you can create the equation of the parabola.