Germinal Pierre Dandelin

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Germinal Pierre Dandelin.

Germinal Pierre Dandelin (born April 12, 1794 in Le Bourget , † February 15, 1847 in Ixelles ) was a Belgian mathematician .

His main field of work were conic sections . Dandelin's spheres are named after Dandelin : one or two spheres, all of which touch the surface lines of a straight circular cone and a cutting plane at the focal points of the resulting conic section; the dandelin spheres serve to derive the properties of conic sections.

Dandelin studied at the École polytechnique in Paris and fought in Napoleon's armies . After his defeat he returned to Belgium and became an engineer in the army, but also taught as a professor in Liège .

He also developed a method for the numerical solution of algebraic equations from 1823, which was only named after him and Karl Heinrich Gräffe , who developed it from 1833, although this is now the so-called Dandelin-Gräffe method, independently of these two, also by Nikolai Ivanovich Lobatschewski was already mentioned in his "Textbook of Higher Algebra" (1834) as a "method for the approximate determination of the zeros of polynomials of the nth degree".

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