Sine and cosine

Animation of the sine and cosine curve. Click here to start and stop animation.

The underlying JavaScript code

 var board = JXG.JSXGraph.initBoard('box', {originX: 200, originY: 200, unitX: 150, unitY: 150});
 var board2 = JXG.JSXGraph.initBoard('box2', {originX: 50, originY: 200, unitX: 50, unitY: 150});
 var xax1 = board.create('axis', [[0,0], [0,1]]);
 var yax1 = board.create('axis', [[0,0], [1,0]]);
 var xax2 = board2.create('axis', [[0,0], [1,0]]);
 board2.create('axis', [[0,0], [0,1]]);

 board2.create('ticks', [xax2, [Math.PI, 2*Math.PI]], {strokeColor: 'green', strokeWidth: '2px'});

 var b1c1 = board.create('circle', [[0,0], [1,0]]);
 var b1p1 = board.create('point', [2, 0], {slideObject: b1c1});
 var perp = board.create('perpendicular', [xax1,b1p1],{strokeColor:['#ff0000',null],visible:[true,false]});
 var perp2 = board.create('perpendicular',[yax1,b1p1],{strokeColor:['#0000ff',null],visible:[true,false]});

 // sine:
 var b2p1 = board2.create('point', [
             function(){ return board.rad([1,0],[0,0],b1p1); }, 
             function() { return b1p1.Y() }], 
             {fixed: true, trace: true, strokeColor: '#ff0000', name: 'S'});
 // cosine:
 var b2p2 = board2.create('point', [
             function(){ return board.rad([1,0],[0,0],b1p1); }, 
             function() { return b1p1.X() }], 
             {fixed: true, trace: true, strokeColor: '#0000ff', name: 'C'});
 // Dependencies (only necessary if b2p1 or b2p2 is deleted)
 b1p1.addChild(b2p1);
 b1p1.addChild(b2p2);

 board.addChild(board2);
        
 // Animation
 var animated = false;
 function animate(point, direction, count) {
    if(animated) {
       point.stopAnimation();
       animated = false;
    } else {
       point.startAnimation(direction, count);
       animated = true;
    }
 }
</script>