Limacon

With JSXGraph elements can be traced to visualize construced loci.

References

• http://en.wikipedia.org/wiki/Limacon

The underlying JavaScript code

        var board = JXG.JSXGraph.initBoard('jxgbox', {originX: 50, originY: 400, unitX: 25, unitY: 25});
        var xax = board.createElement('axis', [[0,0],[1,0]]);
        var yax = board.createElement('axis', [[0,0],[0,1]]);

        var p3 = board.createElement('point', [8, 4], {style:1,name:"P_{3}",fixed:true});
        var p4 = board.createElement('point', [8, 8], {style:2,name:"P_{4}",fixed:true});
        var c1 = board.createElement('circle', [p4, p3]);

        var p6 = board.createElement('glider', [0, 0, c1], {style:3,name:"P_{6}"});
        var g = board.createElement('line', [p3, p6]);

        var c2 = board.createElement('circle', [p6, 3]);

        var p14_1 = board.createElement('point', [board.intersectionFunc(c2,g,0)], {style:8,name:"M",trace:true});
        var p14_2 = board.createElement('point', [board.intersectionFunc(c2,g,1)], {style:8,name:"N",trace:true});

        function clearTrace() {
                p14_1.clearTrace();
                p14_2.clearTrace();
        }