factor



There was nothing deep or mysterious for me.  I took the modulus 127
from Fabrizio's post.  I did not try to think about what it means.

Perhaps you can explain that.

-sen

On Mon, 12 Feb 2007, Stavros Macrakis wrote:

> On 2/12/07, sen1 at math.msu.edu <sen1 at math.msu.edu> wrote:
>> 
>> Note, in my last post, I did not check to see if -56 is really a root.
>> 
>> In trying to check it, one gets real nonsense.
>> 
>> (%i6) subst(x=-56, x^51+x^22+1);
>> (%o6) -
>> 1437438846217273045233591279433697587696887228686919480393652546754508\
>> 87538187253915320319
>
>
> That's because you weren't calculating with modulus 197 (which only happens
> in the rat package).
>
>  modulus:197$
>  ratsubst(-56,x,x^51+x^22+1) => 36
>
>
> On the other hand,
>> 
>> (%i17) modulus: 127;
>> (%o17)                                127
>> (%i18) polymod(x^51+x^22+1);
>>                                    51    22
>> (%o18)                           x   + x   + 1
>> (%i19) factor(%)$
>> 
>> (%i20) p(u):= subst(x=u,factor(%o18));
>> (%o20)                p(u) := subst(x = u, factor(%o18))
>> (%i21) p(-56);
>> (%o21)                                 0
>> (%i22)
>> 
>> So, it seemed to find the root symbolically.
>> 
>
> Sorry, I don't understand the relevance of the mod 127 result for mod 197.
> Is this a typo, or some deep mathematical connection that's eluding me?
>
>              -s
>