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Exercise 9.3.6 (Polynomial unsolvable by radicals)
Prove that for every , there is some polynomial of degree 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 . For , assume for sake of contradiction, that every polynomial of degree is solvable by radicals. We would then have that is solvable by radicals, which would imply that is solvable by radicals, hence a contradiction.