Karim Belabas on Tue, 30 Sep 2014 21:11:08 +0200 |
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Re: thue question |
* Ariel Martin Pacetti [2014-09-30 20:45]: > ? S=thueinit(2*x^3 + 2*x^2 + 11*x - 114); > ? thue(S,200) > %2 = [] > > The values (1,0) and (0,-1) give: 2, 114, so shouldn't they be solutions to > the equation? Not sure I understand this one: thue(S,200) looks for solutions of 2*x^3 + 2*x^2*y + 11*x*y^2 - 114*y^3 = 200 which doesn't seem related to the special values you give. As expected, OTOH, you find (21:04) gp > thue(S,2) %1 = [[1, 0]] (21:04) gp > thue(S,114) %2 = [[0, -1]] > BTW, it I want to solve "many" thue equations, is there a way to get "all > the solutions up to a" (which are probably tested in the search). What do you mean by "solutions up to a" ? Such that max(|x|,|y|) <= a ? If so, either loop over pairs (x,y) [ a^2 trials, optimal for small a ] or only over x and for each such use nfrootsQ() [ better for large a ] Cheers, K.B. -- Karim Belabas, IMB (UMR 5251) Tel: (+33) (0)5 40 00 26 17 Universite de Bordeaux Fax: (+33) (0)5 40 00 69 50 351, cours de la Liberation http://www.math.u-bordeaux1.fr/~kbelabas/ F-33405 Talence (France) http://pari.math.u-bordeaux1.fr/ [PARI/GP] `