“Witch of Agnesi” animation.

Found this fascinating link to the historically famous (1748) “Witch of Agnesi” curve which I read about in Jennifer Ouolette’s very readable book The Calculus Diaries, courtesy of Mildura library. You will need java to activate the applet. Persevere; my browser initially blocked the javascript.
http://dynamicgeometry.com/JavaSketchpad/Gallery/Trigonometry_and_Analytic_Geometry/The_Witch_of_Agnesi.html