François Apéry
3 articles published in Tangente
History and CultureN°210Feb 23, 2023Assigning a value… to a divergent series!
Beyond the "classical" convergence of numerical series, many methods—some particularly powerful—can accelerate the convergence of a series or even assign a value to the "sum of a divergent series." Here are a few notable examples.
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History and CultureN°210Feb 22, 2023Infinite sums: a matter of convention
Equality between two numbers poses no difficulty when both are defined by "finitary"* methods. But as soon as infinity enters the picture—represented by ellipses in formulas—the door opens to all manner of paradoxes. (* Finitism is an approach to mathematics that considers only finite objects.)
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Math for everyoneN°185Nov 21, 2018The campylograph
At the end of the 19th century, Father Dechevrens, director of the Jersey observatory, devised a curve-drawing machine. Originally designed to plot the paths of the planets as seen from Earth, it could produce many other curves besides epicycles!
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