Change Equation of a Graph
From JSXGraph Wiki
This example shows how you can change the equation of a graph without creating the whole construction again.
HowTo of this construction
Adding a text input field somewhere on the page
<input type="text" id="eingabe" value="Math.sin(x)*Math.cos(x)">
Setting up the board
board = JXG.JSXGraph.initBoard('jxgbox', {originX: 250, originY: 250, unitX: 40, unitY: 20});
// Axes
b1axisx = board.createElement('axis', [[1,0], [0,0]], {});
b1axisy = board.createElement('axis', [[0,1], [0,0]], {});