Daniel Lignon
91 articles published in Tangente
Math for everyoneN°196Oct 12, 2020When errors propagate...
Error is inseparable from scientific computation. Calculations of this kind inevitably involve errors. However, it is essential to know where they may come from, to keep them under control, and to estimate their order of magnitude so as to determine whether a result is reliable.
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Math for everyoneN°74Apr 17, 2020Essential references
The Mathcurve website is essential reading for anyone interested in curves. Several major authors are also closely associated with the subject.
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Math for everyoneN°74Apr 15, 2020An algebraic stroll
Algebraic curves come in every degree and every variety. They can be represented in the real plane, the complex plane or even the projective plane. How can we find our way around? Learn to recognize them and navigate this rich geometric universe!
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Math for everyoneN°74Apr 15, 2020Equations for curves
There are essentially two ways to define a plane curve using equations: with a Cartesian (or implicit) equation, or with parametric equations.
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KnowledgeN°74Apr 15, 2020A precise definition? Not so simple!
Surely the modern era has finally given us a precise, rigorous and general definition of a curve. Yet it has not! Neither analysis nor topology has so far produced a definition of "curve" on which everyone agrees.
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InterviewN°74Apr 15, 2020An elusive geometric concept
Almost two thousand years of geometry! That is how long it took, with Descartes, to develop the first tools for studying those mathematical objects we all think we know: curves. How far we have come since the tentative explorations of ancient Greek scholars!
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Math for everyoneNov 25, 2019The audioactive sequence
Self-describing sequences are fairly well known among mathematics enthusiasts, but their history often is not. Even less familiar, no doubt, is the work of the man who helped bring them into the mathematical mainstream: John Conway, who devoted his life to having fun with mathematics.
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