<iframe 
    src="https://jsxgraph.org/share/iframe/continuous-function-non-uniform-continuous-example" 
    style="border: 1px solid black; overflow: hidden; width: 550px; aspect-ratio: 55 / 65;" 
    name="JSXGraph example: Continuous function: non-uniform continuous example" 
    allowfullscreen
></iframe>

<div id="board-0-wrapper" class="jxgbox-wrapper " style="width: 100%; ">
   <div id="board-0" class="jxgbox" style="aspect-ratio: 1 / 1; width: 100%;" data-ar="1 / 1"></div>
</div>

<script type = "text/javascript"> 
    /*
    This example is licensed under a 
    Creative Commons Attribution 4.0 International License.
    https://creativecommons.org/licenses/by/4.0/
    
    Please note you have to mention 
    The Center of Mobile Learning with Digital Technology
    in the credits.
    */
    
    const BOARDID = 'board-0';

    const board = JXG.JSXGraph.initBoard(BOARDID, {boundingbox: [-1, 10, 2, -2], axis: true});
    
     var f = (x) => 1.0 / x;
     var graph = board.create('functiongraph', [f,0.00001, 15], {strokeColor:'#0000ff'});
    
     var s = board.create('slider', [[0,-1],[1.5,-1],[0,1,1]], {name:'&epsilon;'});
    
     var x1 = board.create('glider', [1/2, 0, board.defaultAxes.x], {name:'a'});
    
    // Helper points on x-axis
     var y1 = board.create('point', [0, () => f(x1.X())], {size:2, face:'[]', name:'f(a)'});
     var y2 = board.create('point', [0, () => f(x1.X())-s.Value()], {size:2, face:'[]', name:' '});
     var y3 = board.create('point', [0, () => f(x1.X())+s.Value()], {size:2, face:'[]', name:' '});
    
    //  Helper points on curve
     var z1 = board.create('point', [() => f(y1.Y()), () => y1.Y()], {size:2, face:'[]', name:' '});
     var z2 = board.create('point', [() => f(y2.Y()), () => y2.Y()], {size:2, face:'[]', name:' '});
     var z3 = board.create('point', [() => f(y3.Y()), () => y3.Y()], {size:2, face:'[]', name:' '});
    
    // Horizontal helper lines
     var v1 = board.create('segment', [z1,y1], {strokeColor:'gray', dash:2, strokeWidth:1});
     var v2 = board.create('line', [z2,y2], {strokeColor:'gray', dash:2, strokeWidth:1});
     var v3 = board.create('line', [z3,y3], {strokeColor:'gray', dash:2, strokeWidth:1});
    
    // Vertical helper lines
     var h1 = board.create('curve', [(t) => z1.X(), (t) => t, 0, 20], {strokeColor:'gray',dash:2,strokeWidth:1});
     var h2 = board.create('curve', [(t) => z2.X(), (t) => t, 0, 20], {strokeColor:'gray',dash:2,strokeWidth:1});
     var h3 = board.create('curve', [(t) => z3.X(), (t) => t, 0, 20], {strokeColor:'gray',dash:2,strokeWidth:1});
    
    // Display maximum possible delta for given epsilon
     var txt = board.create('text', [1.2, 4.3, function() { 
                return '&delta; = ' + Math.min(z1.X() - z3.X(), z2.X() - z1.X()).toFixed(5); }]);
    
 </script> 

<jsxgraph width="100%" aspect-ratio="1 / 1" title="Continuous function: non-uniform continuous example" description="This construction was copied from JSXGraph examples database: BTW HERE SHOULD BE A GENERATED LINKuseGlobalJS="false">
   /*
   This example is licensed under a 
   Creative Commons Attribution 4.0 International License.
   https://creativecommons.org/licenses/by/4.0/
   
   Please note you have to mention 
   The Center of Mobile Learning with Digital Technology
   in the credits.
   */
   
   const board = JXG.JSXGraph.initBoard(BOARDID, {boundingbox: [-1, 10, 2, -2], axis: true});
   
    var f = (x) => 1.0 / x;
    var graph = board.create('functiongraph', [f,0.00001, 15], {strokeColor:'#0000ff'});
   
    var s = board.create('slider', [[0,-1],[1.5,-1],[0,1,1]], {name:'&epsilon;'});
   
    var x1 = board.create('glider', [1/2, 0, board.defaultAxes.x], {name:'a'});
   
   // Helper points on x-axis
    var y1 = board.create('point', [0, () => f(x1.X())], {size:2, face:'[]', name:'f(a)'});
    var y2 = board.create('point', [0, () => f(x1.X())-s.Value()], {size:2, face:'[]', name:' '});
    var y3 = board.create('point', [0, () => f(x1.X())+s.Value()], {size:2, face:'[]', name:' '});
   
   //  Helper points on curve
    var z1 = board.create('point', [() => f(y1.Y()), () => y1.Y()], {size:2, face:'[]', name:' '});
    var z2 = board.create('point', [() => f(y2.Y()), () => y2.Y()], {size:2, face:'[]', name:' '});
    var z3 = board.create('point', [() => f(y3.Y()), () => y3.Y()], {size:2, face:'[]', name:' '});
   
   // Horizontal helper lines
    var v1 = board.create('segment', [z1,y1], {strokeColor:'gray', dash:2, strokeWidth:1});
    var v2 = board.create('line', [z2,y2], {strokeColor:'gray', dash:2, strokeWidth:1});
    var v3 = board.create('line', [z3,y3], {strokeColor:'gray', dash:2, strokeWidth:1});
   
   // Vertical helper lines
    var h1 = board.create('curve', [(t) => z1.X(), (t) => t, 0, 20], {strokeColor:'gray',dash:2,strokeWidth:1});
    var h2 = board.create('curve', [(t) => z2.X(), (t) => t, 0, 20], {strokeColor:'gray',dash:2,strokeWidth:1});
    var h3 = board.create('curve', [(t) => z3.X(), (t) => t, 0, 20], {strokeColor:'gray',dash:2,strokeWidth:1});
   
   // Display maximum possible delta for given epsilon
    var txt = board.create('text', [1.2, 4.3, function() { 
               return '&delta; = ' + Math.min(z1.X() - z3.X(), z2.X() - z1.X()).toFixed(5); }]);
   
</jsxgraph>