2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)\tan^{-1} \left(\sqrt{\sqrt[3]{{\left(\frac{1 - x}{x + 1}\right)}^{3}}}\right) \cdot 2double f(double x) {
double r13127 = 2.0;
double r13128 = 1.0;
double r13129 = x;
double r13130 = r13128 - r13129;
double r13131 = r13128 + r13129;
double r13132 = r13130 / r13131;
double r13133 = sqrt(r13132);
double r13134 = atan(r13133);
double r13135 = r13127 * r13134;
return r13135;
}
double f(double x) {
double r13136 = 1.0;
double r13137 = x;
double r13138 = r13136 - r13137;
double r13139 = r13137 + r13136;
double r13140 = r13138 / r13139;
double r13141 = 3.0;
double r13142 = pow(r13140, r13141);
double r13143 = cbrt(r13142);
double r13144 = sqrt(r13143);
double r13145 = atan(r13144);
double r13146 = 2.0;
double r13147 = r13145 * r13146;
return r13147;
}



Bits error versus x
Results
Initial program 0.0
Simplified0.0
rmApplied add-cbrt-cube0.0
Applied add-cbrt-cube0.0
Applied cbrt-undiv0.0
Simplified0.0
Final simplification0.0
herbie shell --seed 2019179
(FPCore (x)
:name "arccos"
(* 2.0 (atan (sqrt (/ (- 1.0 x) (+ 1.0 x))))))