2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)2 \cdot \tan^{-1} \left(\sqrt{\sqrt[3]{{\left(\frac{1 - x}{1 + x}\right)}^{3}}}\right)double f(double x) {
double r8012 = 2.0;
double r8013 = 1.0;
double r8014 = x;
double r8015 = r8013 - r8014;
double r8016 = r8013 + r8014;
double r8017 = r8015 / r8016;
double r8018 = sqrt(r8017);
double r8019 = atan(r8018);
double r8020 = r8012 * r8019;
return r8020;
}
double f(double x) {
double r8021 = 2.0;
double r8022 = 1.0;
double r8023 = x;
double r8024 = r8022 - r8023;
double r8025 = r8022 + r8023;
double r8026 = r8024 / r8025;
double r8027 = 3.0;
double r8028 = pow(r8026, r8027);
double r8029 = cbrt(r8028);
double r8030 = sqrt(r8029);
double r8031 = atan(r8030);
double r8032 = r8021 * r8031;
return r8032;
}



Bits error versus x
Results
Initial program 0.0
rmApplied add-cbrt-cube0.0
Applied add-cbrt-cube0.0
Applied cbrt-undiv0.0
Simplified0.0
Final simplification0.0
herbie shell --seed 2020002
(FPCore (x)
:name "arccos"
:precision binary64
(* 2 (atan (sqrt (/ (- 1 x) (+ 1 x))))))