Difference between revisions of "Lituus"
From JSXGraph Wiki
Jump to navigationJump to searchA WASSERMANN (talk | contribs) |
A WASSERMANN (talk | contribs) |
||
| Line 20: | Line 20: | ||
</jsxgraph> | </jsxgraph> | ||
</source> | </source> | ||
| + | ===Other curves=== | ||
| + | The quadrifolium is a type of rose curve with n=2. It has polar equation: | ||
| + | |||
| + | :<math> r = \cos(2\theta), \,</math> | ||
| + | |||
| + | with corresponding algebraic equation | ||
| + | |||
| + | :<math> (x^2+y^2)^3 = (x^2-y^2)^2. \, </math> | ||
<jsxgraph width="500" height="500" box="box2"> | <jsxgraph width="500" height="500" box="box2"> | ||
Revision as of 17:10, 18 March 2009
A lituus is a spiral in which the angle is inversely proportional to the square of the radius (as expressed in polar coordinates).
- [math]r^2\theta = k \,[/math]
The JavaScript code to produce this picture
<jsxgraph width="500" height="500" box="box1">
var b1 = JXG.JSXGraph.initBoard('box1', {axis:true,originX: 250, originY: 250, unitX: 25, unitY: 25});
var k = b1.createElement('slider', [[1,8],[5,8],[0,1,4]]);
var c = b1.createElement('curve', [function(phi){return Math.sqrt(k.Value()/phi); }, [0, 0],0, 8*Math.PI],
{curveType:'polar', strokewidth:4});
</jsxgraph>
Other curves
The quadrifolium is a type of rose curve with n=2. It has polar equation:
- [math] r = \cos(2\theta), \,[/math]
with corresponding algebraic equation
- [math] (x^2+y^2)^3 = (x^2-y^2)^2. \, [/math]
