Given is a unit circle [math]c[/math] and a fixed point [math]C[/math] on the circle. [br]Let [math]R[/math] be a random point on the circle, and let [math]a[/math] be the line through [math]C[/math] and [math]R[/math]. [br]The slider [math]d[/math] allows us to choose and fix a distance [math]d[/math]. [br]The light blue points [math]D[/math] and [math]E[/math] are points from the line, on a distance [math]d[/math] to [math]R[/math]. [br]As [math]R[/math] moves along the circle, the points [math]D[/math] and [math]E[/math] will draw the conchoid of the circle - a Limaçon.[br][list][br][*]Drag the slider to see how the shape of the Limaçon depends on the distance [math]d[/math].[br][/list]