2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)\tan^{-1} \left(\sqrt{\log \left(e^{\frac{1 - x}{1 + x}}\right)}\right) \cdot 2double f(double x) {
double r256615 = 2.0;
double r256616 = 1.0;
double r256617 = x;
double r256618 = r256616 - r256617;
double r256619 = r256616 + r256617;
double r256620 = r256618 / r256619;
double r256621 = sqrt(r256620);
double r256622 = atan(r256621);
double r256623 = r256615 * r256622;
return r256623;
}
double f(double x) {
double r256624 = 1.0;
double r256625 = x;
double r256626 = r256624 - r256625;
double r256627 = r256624 + r256625;
double r256628 = r256626 / r256627;
double r256629 = exp(r256628);
double r256630 = log(r256629);
double r256631 = sqrt(r256630);
double r256632 = atan(r256631);
double r256633 = 2.0;
double r256634 = r256632 * r256633;
return r256634;
}



Bits error versus x
Results
Initial program 0.0
rmApplied add-log-exp0.0
Final simplification0.0
herbie shell --seed 2019130
(FPCore (x)
:name "arccos"
(* 2 (atan (sqrt (/ (- 1 x) (+ 1 x))))))