2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)\tan^{-1} \left(\sqrt{\frac{1}{\sqrt{1 + x}} \cdot \sqrt[3]{\frac{1 - x}{\sqrt{1 + x}} \cdot \left(\frac{1 - x}{\sqrt{1 + x}} \cdot \frac{1 - x}{\sqrt{1 + x}}\right)}}\right) \cdot 2double f(double x) {
double r2756718 = 2.0;
double r2756719 = 1.0;
double r2756720 = x;
double r2756721 = r2756719 - r2756720;
double r2756722 = r2756719 + r2756720;
double r2756723 = r2756721 / r2756722;
double r2756724 = sqrt(r2756723);
double r2756725 = atan(r2756724);
double r2756726 = r2756718 * r2756725;
return r2756726;
}
double f(double x) {
double r2756727 = 1.0;
double r2756728 = x;
double r2756729 = r2756727 + r2756728;
double r2756730 = sqrt(r2756729);
double r2756731 = r2756727 / r2756730;
double r2756732 = r2756727 - r2756728;
double r2756733 = r2756732 / r2756730;
double r2756734 = r2756733 * r2756733;
double r2756735 = r2756733 * r2756734;
double r2756736 = cbrt(r2756735);
double r2756737 = r2756731 * r2756736;
double r2756738 = sqrt(r2756737);
double r2756739 = atan(r2756738);
double r2756740 = 2.0;
double r2756741 = r2756739 * r2756740;
return r2756741;
}



Bits error versus x
Results
Initial program 0.0
rmApplied add-sqr-sqrt0.0
Applied *-un-lft-identity0.0
Applied *-un-lft-identity0.0
Applied distribute-lft-out--0.0
Applied times-frac0.0
rmApplied add-cbrt-cube0.0
Final simplification0.0
herbie shell --seed 2019124
(FPCore (x)
:name "arccos"
(* 2 (atan (sqrt (/ (- 1 x) (+ 1 x))))))