Bounding box

The bounding box defines the viewport of the board, i.e. the portion of the [math]\displaystyle{ \mathbb{R}^2 }[/math] that is shown. The JavaScript code

var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,10,5,-2], keepaspectratio: true, axis:true});

sets the vertical and horizontal units and the position of the origin such that the upper left corner of the drawing panel has position (-5,10) and the lower right corner of the drawing panel has position (5,-2).

The source code of the page looks like this:

<link rel="stylesheet" type="text/css" href="https://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
<script type="text/javascript" src="https://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<div id="jxgbox" class="jxgbox" style="width:500px; height:600px;"></div>
<script type="text/javascript">
var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,10,5,-2], axis:true});
</script>