Rotate text
From JSXGraph Wiki
Text can be rotated with CSS transformations. In that case JSXGraph text elements have to be realized with HTML div elements, which is the default case.
The CSS/JavaScript source code
#my_t {
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=3);
}
The CSS and the JavaScript code is linked via the id my_t of the text element.
var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-5,5,5,-5], grid:true});
var s = brd.create('slider',[[-3,0],[3,0],[0,1,10]], {name:'s'});
var t = brd.create('text',[0,2,function(){return 'text = '+s.Value().toFixed(3);}],{id:'my_t'});