In this article, the principal n-th root of a complex number is defined, the Vieta's formulas for polynomial equations of degree 2, 3 and 4 are formalized. The solution of quadratic equations, the Cardan's solution of cubic equations and the Descartes-Euler solution of quartic equations in terms of their complex coefficients are also presented [5].
@article{bwmeta1.element.doi-10_2478_v10037-009-0012-z,
author = {Marco Riccardi},
title = {Solution of Cubic and Quartic Equations},
journal = {Formalized Mathematics},
volume = {17},
year = {2009},
pages = {117-122},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.doi-10_2478_v10037-009-0012-z}
}
Marco Riccardi. Solution of Cubic and Quartic Equations. Formalized Mathematics, Tome 17 (2009) pp. 117-122. http://gdmltest.u-ga.fr/item/bwmeta1.element.doi-10_2478_v10037-009-0012-z/
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