GraphingCalculator 3.5;
Window 44 0 638 665;
PaneDivider 260;
Slider 0 2;
SliderSteps 20;
SliderControlValue 9;
SliderVariable b;
T 0 6.2;
2D.Scale 0.1 0.1 5 5;
2D.BottomLeft -0.9375 -1.88125;
Expr [[x-a]^2+y^2]*[[x+a]^2+y^2]=b^4;
Text "This curve is known as Cassinian Oval. It is defined as the locus of points P such that distance[P,F1] * distance[P,F2] == b^2, where F1 and F2 are two fixed points (foci) and b is a constant. It is analogous to the definition of __ellipse__, where sum of two distances is replace by product. In this equation, the foci are at (-1,0) and (1,0). When a==1, the curve is known as lemniscate of Bernoulli.
xahlee.org, 2004";