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Exercise 9.3.6 (Polynomial unsolvable by radicals)

Prove that for every n 5, there is some polynomial of degree n that is not solvable by radicals.

Answers

Solution: By Theorem 9.3.5 we have that not every polynomial of degree 5 is solvable by radicals, let one such polynomial be f(t). For n > 5, assume for sake of contradiction, that every polynomial of degree n is solvable by radicals. We would then have that f(t) tn5 is solvable by radicals, which would imply that f(t) is solvable by radicals, hence a contradiction.

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2022-11-30 03:41
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