See if poissimp() does the trick.
It works only for sin(...) of x,y,z,u,v,w probably.
Daniel Martins wrote:
>
> I have a problem for a long time. I am trying to avoid the expansion
> of term like
>
> sin(A+B)+sin(A-B)
>
> I know that my results will be functions of sin(A+B+C+...) and
> cos(A+B+C+...) etc... but in the middle of the generation process
> appear lots of terms like
>
> sin(A+B)+sin(A-B)
> sin(A+B+C)+sin(A+B-C)
>
> so one alternative is to avoid that these term grow. However I could
> not do this up to now.
>
> Any help will be very important.
>
> Daniel
>
> (C4) matchdeclare([A,B],true);
>
> (D4) DONE
>
> (... lots of trials ... and again to the beginning )
>
> (C122) defrule(cAB2,sin(A+B)+sin(A-B),2*sin(A)*cos(B));
>
> B + A partitions SUM
> (D122) cAB2 : SIN(B + A) - SIN(B - A) -> 2 SIN(A) COS(B)
> (C123) HH:SIN(Y + X) - SIN(Y - X);
>
> (D123) SIN(Y + X) - SIN(Y - X)
> (C124)
> _______________________________________________
> Maxima mailing list
> Maxima@www.math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima