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Solving the quintic by radicals

There is not. Galois explained why: solvability corresponds to a property of the equation's symmetry group, and the symmetric group on five letters lacks it. Galois theory, the tool built to close this question, became one of the foundations of modern algebra.

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Posed 16th century, after Cardano's cubic and Ferrari's quartic formulas. Closed 1824, Niels Henrik Abel (after Ruffini, 1799); explained by Galois, 1832.

Sources

Algebra and groups · Mathematics

Relations

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