Am 04.03.2011 03:17, schrieb Per Ting: > Thanks, tried this one, did not work either. > > Per > > > The parametric functions are not understood. Yo need too rewrite then as >> >> 3*cos(t)^3 | 5*sin(t)^5 Per, did you really had a circunflex before the power values? cos(t)_3 _ must be a ^ Herbert