Inequalities
From JSXGraph Wiki
The JavaScript code
var b = JXG.JSXGraph.initBoard('box1', {boundingbox: [-5, 5, 5, -5], axis:true});
var c = b.create('slider', [[-3,4], [2,4], [-5,0,5]]),
    line1 = b.create('line', [function() { return [c.Value(), 0, -1]; }], {strokeColor: 'black'}),
    ineq1 = b.create('inequality', [line1], {inverse: true}),
    line2 = b.create('line', [1, 2, -1]),
    ineq2 = b.create('inequality', [line2], {inverse: true});
