Re: Posting to Mma mailing list

*To*: mathgroup at yoda.physics.unc.edu*Subject*: Re: Posting to Mma mailing list*From*: "Prof. J.H. Davenport" <J.H.Davenport at maths.bath.ac.uk>*Date*: Tue, 26 May 92 17:36:07 BST

>> So this equals x^4 + a^4 if and only if b^2 = 2 a^2 , that is >> x^4 + n factors over the integers if and only if n = b^4 /4 for b an >> integer This might not be the ONLY way such a polynomial could factor. The result is in fact due to Capelli: Sulla riduttibilita della funzione $x^n-A$ in campo qualunque di rationalit\`a. Math. Ann. 54(1901) pp. 602-603.