Difference between revisions of "Elliptic curves"

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An elliptic curve can be written as a plane algebraic curve defined by an equation of the form
 
An elliptic curve can be written as a plane algebraic curve defined by an equation of the form
 
:<math>    y^2=x^3+ax+b\,. </math>
 
:<math>    y^2=x^3+ax+b\,. </math>
<html>
+
<jsxgraph width="600" height="400" box="jxgbox">
<jsxgraph width="600" height="400" box="box0">
 
 
JXG.Options.axis.strokeColor = '#cccccc';
 
JXG.Options.axis.strokeColor = '#cccccc';
brd = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 200, unitX: 20, unitY: 20, axis:true});
+
brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-15, 10, 15, -10], axis:true});
 
brd.suspendUpdate();
 
brd.suspendUpdate();
var b = brd.create('slider',[[1,-3],[10,-3],[-10,0,10]],{name:'a'});
+
var b = brd.create('slider',[[1,-3],[10,-3],[-10,2.10,10]],{name:'a'});
var a = brd.create('slider',[[1,-4],[10,-4],[-10,0,10]],{name:'b'});
+
var a = brd.create('slider',[[1,-4],[10,-4],[-10,-9.52,10]],{name:'b'});
  
 
var c1 = brd.create('functiongraph', [function(x){ return Math.sqrt(x*x*x+a.Value()*x+b.Value()); }],
 
var c1 = brd.create('functiongraph', [function(x){ return Math.sqrt(x*x*x+a.Value()*x+b.Value()); }],
Line 18: Line 17:
 
<source lang="javascript">
 
<source lang="javascript">
 
JXG.Options.axis.strokeColor = '#cccccc';
 
JXG.Options.axis.strokeColor = '#cccccc';
JXG.Options.axis.strokeColor = '#cccccc';
+
brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-15, 10, 15, -10], 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.create('slider',[[1,-3],[10,-3],[-10,0,10]],{name:'a'});

Latest revision as of 13:42, 28 February 2014

An elliptic curve can be written as a plane algebraic curve defined by an equation of the form

[math] y^2=x^3+ax+b\,. [/math]

JXG.Options.axis.strokeColor = '#cccccc';
brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-15, 10, 15, -10], 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();

References