This evening I saw the Australia Brandenburg Orchestra with guest soloist Lixsania Fernandez, a virtuoso player of the viola da gamba, from Cuba. (Although she studied, and now lives, in Spain.) Lixsania is quite amazing: tall, statuesque, quite absurdly beautiful, and plays with a technique that encompasses the …

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Here’s an example of a transportation problem, with information given as a table: Demands 300 360 280 340 220 750 100 150 200 140 35 Supplies  400 50 70 80 65 80 350 40 90 100 150 130 This is an example of a balanced, non-degenerate transportation problem. It is balanced since the sum of supplies equals the sum of …

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For my elementary linear programming subject, the students (who are all pre-service teachers) use Excel and its Solver as the computational tool of choice. We do this for several reasons: Excel is software with which they’re likely to have had some experience, also it’s used in schools; it also means we don’t have to …

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Here’s an example of a coloured tetrahedron: hello <div oncontextmenu="return false;" id="viewerContext" style = "width:640px;height:470px;" design-url="tetrahedron.jscad"></div> <div id="tail" style="display: none;"> <div id="statusdiv"></div> </div>

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There’s a celebrated elementary result which claims that: There are irrational numbers \(x\) and \(y\) for which \(x^y\) is rational. The standard proof goes like this. Now, we know that \(\sqrt{2}\) is irrational, so let’s consider \(r=\sqrt{2}^\sqrt{2}\). Either \(r\) is rational, or it is not. If it is rational, …

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For years I have been running a blog and other web apps on a VPS running Ubuntu 14.04 and Apache - a standard LAMP system. However, after experimenting with some apps - temporarily installing them and testing them, only to discard them, the system was becoming a total mess. Worst of all, various MySQL files were …

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These are a class of root-finding methods; that is, for the numerical solution of a single nonlinear equation, developed by Alston Scott Householder in 1970. They may be considered a generalisation of the well known Newton-Raphson method (also known more simply as Newton’s method) defined by [ x\leftarrow …

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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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This was a comedy sketch initially performed in the revue “Clowns in Clover” which had its first performance at the Adelphi Theatre in London on December 1, 1927. This particular sketch was written by Dion Titheradge and starred the inimitable Cicely Courtneidge as the annoyed customer Mrs Spooner. It has been recorded …

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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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