On 4/3/07, Poul Riis <Poul.Riis at skolekom.dk> wrote:
> Some CAS-tools come out with a solution to the following problem
> (relativistic case of elastic head on collision):
> solve([p1=p3 + p4,E1 + m2=E3 + E4,E3^2=p3^2 + m1^2,E4^2=p4^2 + m2^2],[p3,
> E3, p4, E4]);
> but unfortunately maxima does not.
> Is there some variant of solve that can do better? Or am I doing something
> wrong?
Since I'm already advertising Solver in some other thread:
(%i1) load(solver)$
(%i2) Solve_Inconsistent_Terms : []$ /* A workaround for a bug in
maxima 5.11 */
(%i3) Solver([p1=p3+p4,E1+m2=E3+E4,E3^2=p3^2+m1^2,E4^2=p4^2+m2^2],[p3,E3,p4,E4],[p1,m1,m2,E1]);
(%o3) [[p3=sqrt(E4^2-m2^2)+p1,p4=-sqrt(E4^2-m2^2),E3=-sqrt(2*p1*sqrt(E4^2-m2^2)+E4^2+p1^2-m2^2+m1^2)],[p3=p1
-sqrt(E4^2-m2^2),p4=sqrt(E4^2-m2^2),E3=-sqrt(-2*p1*sqrt(E4^2-m2^2)+E4^2+p1^2-m2^2+m1^2)],[p3=sqrt(E4^2-m2^2)+p1,p4=
-sqrt(E4^2-m2^2),E3=sqrt(2*p1*sqrt(E4^2-m2^2)+E4^2+p1^2-m2^2+m1^2)],[p3=p1-sqrt(E4^2-m2^2),p4=sqrt(E4^2-m2^2),E3=
sqrt(-2*p1*sqrt(E4^2-m2^2)+E4^2+p1^2-m2^2+m1^2)]]
I don't know if these solutions make sense.
--
Andrej