Introduction Poncelet’s porism or Poncelet’s closure theorem is one of the most remarkable results in plane geometry. It is most easily described in terms of circles: suppose we have two circles \(C\) and \(D\), with \(D\) lying entirely inside \(C\). Pick a point \(p_0\) on \(C\), and find the tangent from \(p_0\) to …

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The Joukowksy Transform is an elegant and simple way to create an airfoil shape. Let \(C\) be a circle in the complex plane that passes through the point \(z=1\) and encompasses the point \(z=-1\). The transform is defined as

\[ \zeta=z+\frac{1}{z}. \]

We can explore the transform by looking at the circles centred at …

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I recently came across some nice material on John Cook’s blog about equations that described eggs. It turns out there are vast number of equations whose graphs are egg-shaped: that is, basically ellipse shape, but with one end “rounder” than the other. You can see lots at Jürgen Köller’s Mathematische Basteleien page. …

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JSXGraph is a graphics package deveoped in Javascript, and which seems to be tailor-made for a static blog such as this. It consists of only two files: the javascript file itself, and an accompanying css file, which you can download. Alternaively you can simply link to the online files at the Javascript content …

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