Difference between revisions of "Logarithmic spiral"
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A WASSERMANN (talk  contribs) 
A WASSERMANN (talk  contribs) 
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Latest revision as of 14:50, 28 June 2019
It can be described in polar coordinates [math](r, \theta)[/math] by the equation
 [math]r = ae^{b\theta}\,[/math]
with real numbers [math]a[/math] and [math]b[/math].
The JavaScript code to produce this picture
board = JXG.JSXGraph.initBoard('jsxgbox', {boundingbox: [10, 10, 10, 10]});
var a = board.create('slider', [[1,1],[5,1],[0,0.3,1]],{name:'a'});
var b = board.create('slider', [[1,2],[5,2],[1,0.15,1]],{name:'b'});
var c = board.create('curve', [function(phi){return a.Value()*JXG.Math.pow(Math.E,b.Value()*phi); }, [0, 0],0, 8*Math.PI],
{curveType:'polar', strokewidth:4});
var g = board.create('glider', [c]);
var t = board.create('tangent', [g], {dash:2,strokeColor:'#a612a9'});