double cfracTan(double x, unsigned int n){
 30     double xx = x*x;
 31     int l = 1;
 32     double eps = 0.0000000001;
 33     double result = x;
 34     double xp;
 35     while (abVal(result-xp) >= eps){
 36          xp = result;
 37          result = xp/l-xx;
 38          l = l + 2;
 39     }
 40 return result;