2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)2 \cdot \tan^{-1} \left(\frac{\sqrt{1 - x}}{\sqrt{1 + x}}\right)double f(double x) {
double r586665 = 2.0;
double r586666 = 1.0;
double r586667 = x;
double r586668 = r586666 - r586667;
double r586669 = r586666 + r586667;
double r586670 = r586668 / r586669;
double r586671 = sqrt(r586670);
double r586672 = atan(r586671);
double r586673 = r586665 * r586672;
return r586673;
}
double f(double x) {
double r586674 = 2.0;
double r586675 = 1.0;
double r586676 = x;
double r586677 = r586675 - r586676;
double r586678 = sqrt(r586677);
double r586679 = r586675 + r586676;
double r586680 = sqrt(r586679);
double r586681 = r586678 / r586680;
double r586682 = atan(r586681);
double r586683 = r586674 * r586682;
return r586683;
}



Bits error versus x
Results
Initial program 0.0
rmApplied sqrt-div0.0
Final simplification0.0
herbie shell --seed 2019172 +o rules:numerics
(FPCore (x)
:name "arccos"
(* 2.0 (atan (sqrt (/ (- 1.0 x) (+ 1.0 x))))))