2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)2 \cdot \tan^{-1} \left(\frac{\sqrt{1 - x \cdot \left(x \cdot x\right)}}{\sqrt{1 + \left(x \cdot x + x\right)} \cdot \sqrt{1 + x}}\right)double f(double x) {
double r1081504 = 2.0;
double r1081505 = 1.0;
double r1081506 = x;
double r1081507 = r1081505 - r1081506;
double r1081508 = r1081505 + r1081506;
double r1081509 = r1081507 / r1081508;
double r1081510 = sqrt(r1081509);
double r1081511 = atan(r1081510);
double r1081512 = r1081504 * r1081511;
return r1081512;
}
double f(double x) {
double r1081513 = 2.0;
double r1081514 = 1.0;
double r1081515 = x;
double r1081516 = r1081515 * r1081515;
double r1081517 = r1081515 * r1081516;
double r1081518 = r1081514 - r1081517;
double r1081519 = sqrt(r1081518);
double r1081520 = r1081516 + r1081515;
double r1081521 = r1081514 + r1081520;
double r1081522 = sqrt(r1081521);
double r1081523 = r1081514 + r1081515;
double r1081524 = sqrt(r1081523);
double r1081525 = r1081522 * r1081524;
double r1081526 = r1081519 / r1081525;
double r1081527 = atan(r1081526);
double r1081528 = r1081513 * r1081527;
return r1081528;
}



Bits error versus x
Results
Initial program 0.0
rmApplied sqrt-div0.0
rmApplied flip3--0.0
Applied sqrt-div0.0
Applied associate-/l/0.0
Simplified0.0
Final simplification0.0
herbie shell --seed 2019121
(FPCore (x)
:name "arccos"
(* 2 (atan (sqrt (/ (- 1 x) (+ 1 x))))))