Elliptic curves: Difference between revisions
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brd = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 200, unitX: 20, unitY: 20, axis:true}); | brd = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 200, unitX: 20, unitY: 20, axis:true}); | ||
brd.suspendUpdate(); | brd.suspendUpdate(); | ||
var b = brd.create('slider',[[1,-3],[10,-3],[-10,0,10]],{name:'a'}); | |||
var b = brd. | var a = brd.create('slider',[[1,-4],[10,-4],[-10,0,10]],{name:'b'}); | ||
var a = brd. | |||
var c1 = brd.create('functiongraph', [function(x){ return Math.sqrt(x*x*x+a.Value()*x+b.Value()); }], | |||
{strokeWidth:3,strokeColor:'black'}); | |||
var c2 = brd.create('functiongraph', [function(x){ return -Math.sqrt(x*x*x+a.Value()*x+b.Value()); }], | |||
{strokeWidth:3,strokeColor:'black'}); | |||
brd.unsuspendUpdate(); | brd.unsuspendUpdate(); | ||
</script> | </script> | ||
Line 26: | Line 26: | ||
</source> | </source> | ||
<source lang="javascript"> | <source lang="javascript"> | ||
brd = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 200, unitX: 20, unitY: 20}); | JXG.Options.axis.strokeColor = '#cccccc'; | ||
brd = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 200, unitX: 20, unitY: 20, axis:true}); | |||
brd.suspendUpdate(); | brd.suspendUpdate(); | ||
var b = brd.create('slider',[[1,-3],[10,-3],[-10,0,10]],{name:'a'}); | |||
var a = brd.create('slider',[[1,-4],[10,-4],[-10,0,10]],{name:'b'}); | |||
var b = brd. | |||
var a = brd. | |||
var c1 = brd.create('functiongraph', [function(x){ return Math.sqrt(x*x*x+a.Value()*x+b.Value()); }], | |||
{strokeWidth:3,strokeColor:'black'}); | |||
var c2 = brd.create('functiongraph', [function(x){ return -Math.sqrt(x*x*x+a.Value()*x+b.Value()); }], | |||
{strokeWidth:3,strokeColor:'black'}); | |||
brd.unsuspendUpdate(); | brd.unsuspendUpdate(); | ||
</source> | </source> |
Revision as of 07:22, 4 August 2010
An elliptic curve can be written as a plane algebraic curve defined by an equation of the form
- [math]\displaystyle{ y^2=x^3+ax+b\,. }[/math]
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<div id="jxgbox" class="jxgbox" style="width:600px; height:400px;"></div>
JXG.Options.axis.strokeColor = '#cccccc';
brd = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 200, unitX: 20, unitY: 20, axis:true});
brd.suspendUpdate();
var b = brd.create('slider',[[1,-3],[10,-3],[-10,0,10]],{name:'a'});
var a = brd.create('slider',[[1,-4],[10,-4],[-10,0,10]],{name:'b'});
var c1 = brd.create('functiongraph', [function(x){ return Math.sqrt(x*x*x+a.Value()*x+b.Value()); }],
{strokeWidth:3,strokeColor:'black'});
var c2 = brd.create('functiongraph', [function(x){ return -Math.sqrt(x*x*x+a.Value()*x+b.Value()); }],
{strokeWidth:3,strokeColor:'black'});
brd.unsuspendUpdate();