Tom Torfs wrote: > > How can I get Maxima to recognize that sin(phi)^2+cos(phi)^2 = 1 ? Without this type of simplification, the solutions of my system will get huge and ugly. trigsimp(sin(x)^2+cos(x)^2) -> 1 You may want to try "?? trig" to find out about some other trig simplifications routines. Ray