Power series for the exponential function

References

• http://en.wikipedia.org/wiki/Exponential_function

The underlying JavaScript code

// Board
board1 = JXG.JSXGraph.initBoard('jxgbox1', {originX: 300, originY: 250, unitX: 50, unitY: 10});
board1.suspendUpdate();
// Axes and Properties
board1.createElement('axis', [[0,0], [1,0]], {});
board1.createElement('axis', [[0,0], [0,1]], {});
//
board1.createElement('functiongraph', 
        [function(t){ return Math.exp(t); }, -10, 10],
        {strokeColor: "#cccccc"});
var s = board1.createElement('slider', [[0.75,-2],[5,-2.0],[0,0,15]], {name:'S',snapWidth:1});
board1.createElement('text',[-4,10, function() {
		return 'n='+s.Value();
	}]);
board1.createElement('text',[-4,8, function() {
		var val = 0, i, sv = s.Value()+1;
		for(i = 0; i < sv; i++) {
   			val+= 1.0/board1.factorial(i);
		}
		return 'e~'+board1.round(val,10);
	}]);
board1.createElement('functiongraph', [
	function(t) {
		var val = 0, i, sv = s.Value()+1;
		for(i = 0; i < sv; i++) {
   			val+= Math.pow(t,i)/board1.factorial(i);
		}
		return val;
	},
-10, 10], {strokeColor: "#bb0000", curveType:'plot'});
board1.unsuspendUpdate();