|Georgi Guninski on Thu, 20 Sep 2012 15:35:52 +0200|
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|Re: polresultant disagrees with sage, maxima and magma|
parisize = 8000000, primelimit = 500509 ? q1=x2;q2=x2;polresultant(q1,q2,x1) %1 = 0 ? q1=x2;q2=x2;polresultant(q1,q2,x1) %2 = 0 ? p1=y;p2=y;polresultant(p1,p2,x1) %3 = 1 On Thu, Sep 20, 2012 at 04:09:07PM +0300, Georgi Guninski wrote: > I don't claim this is a bug in pari, more like a bug in the > mentioned CAS. > > ? p1=x2*(x3-x4);p2=x2*(x3-2*x4);polresultant(p1,p2,x1) > %1 = 0 > > Since p1 and p2 certainly have common roots I expect the resultant > w.r.t. x1 (not present in p1 or p2) to be able to vanish. > > sage, maxima and magma return $1$ on the above testcase. > > Can't see how it can be both ways, which is correct?