Given the parabola [math]y^2=2px[/math] and a distance [math]d>\frac{p}{2}[/math], find a line of distance [math]d[/math] from the focus point of the parabola which is tangent to the parabola.[br]In the applet below you the red circle has center [math]F[/math] and radius [math]d[/math]. Moving point [math]A[/math] gives all lines with distance [math]d[/math] from [math]F[/math][br][br]Notice anything interesting? try formulating and then proving.