JXG.Options.text.useKatex = true;
JXG.Options.axis.ticks.majorHeight = 10;
JXG.Options.axis.ticks.insertTicks = false;
JXG.Options.axis.ticks.ticksDistance = 100;
var board = JXG.JSXGraph.initBoard('box1', {
boundingbox:[-10, 10, 10, -10],showNavigation:false, showcopyright: false, axis: true,
});
var F1 = board.create('point', [-6,0],{visible:false});
var F2 = board.create('point', [function(){return -F1.X()},function(){return F1.Y();}],{visible:false});
var p1 = board.create('point', [1,4.5],{name:'',size:0,fixed:true});
var el = board.create('ellipse',[F1,F2,p1],{strokeColor:'red'});
var g1 = board.create('glider', [5.0, 2, el],{visible:false});
//var l1 = board.create('segment', [F1, g1],{strokeWidth:1});
//var l2 = board.create('segment', [F2, g1],{strokeWidth:1});
var x1 = board.create('point', [1,0],{visible:false});
var x2 = board.create('point', [5,0],{visible:false});
var cx = board.create('line', [x1,x2],{visible:false});
var y1 = board.create('point', [0,1],{visible:false});
var y2 = board.create('point', [0,-1],{visible:false});
var cy = board.create('line', [y1,y2],{visible:false});
var i1 = board.create('intersection', [cx, cy],{visible:false});
//var l1 = board.create('segment', [i1, g1],{strokeWidth:1,withLabel:true,name:'',label:{offset:[-30,-15]}});
//var a1 = board.create('angle', [F2, i1, g1],{name:'t', radius:1.5,label:{offset:[3,-12]}});
var vy1 = board.create('intersection', [cy, el],{visible:false});
var vy2 = board.create('intersection', [cy, el,1],{visible:false});
var c1 = board.create('circle', [i1, vy1],{strokeWidth:1});
var vx1 = board.create('intersection', [cx, el],{visible:false});
var vx2 = board.create('intersection', [cx, el,1],{visible:false});
var c2 = board.create('circle', [i1, vx1],{strokeWidth:1});
var g2 = board.create('glider', [4.52, 5.64, c2],{name:'A',size:1,label:{offset:[12,15]}});
var l2 = board.create('segment', [i1,g2],{strokeWidth:1});
var i2 = board.create('intersection', [l2, c1],{name:'B',size:1 });
var pb1 = board.create('point', [0, function(){return i2.Y()}],{visible:false});
var l3 = board.create('line', [pb1,i2],{visible:false});
var i3 = board.create('intersection', [el, l3, 0],{name:'P',size:1,label:{offset:[12,10]}});
var i33 = board.create('intersection', [cy, l3],{visible:false});
var l4 = board.create('segment', [i33, i3],{strokeWidth:1});
var l5 = board.create('line', [g2,i3],{visible:false});
var i4 = board.create('intersection', [l5, cx],{visible:false});
var l6 = board.create('segment', [i4, g2],{strokeWidth:1});
var a1 = board.create('angle', [i4, i1, g2],{name:'t', radius:1.5,label:{offset:[3,-12]}});
var txt1 = board.create('text',[-1,0.5,function(){return 'b sin t';}],{display:'internal',rotate:function(){
ang = 90 ; return ang;
}, fontSize:16 });
var txt1 = board.create('text',[0.2,-1,function(){return 'a \\cos t';}])
