2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)2 \cdot \tan^{-1} \left(\frac{\sqrt{\left(1 \cdot 1 - x \cdot x\right) \cdot \left({\left(1 \cdot 1\right)}^{3} + {\left(x \cdot x - 1 \cdot x\right)}^{3}\right)}}{\sqrt{\left({1}^{3} + {x}^{3}\right) \cdot \left(\left(1 \cdot 1\right) \cdot \left(1 \cdot 1\right) + \left(\left(x \cdot x - 1 \cdot x\right) \cdot \left(x \cdot x - 1 \cdot x\right) - \left(1 \cdot 1\right) \cdot \left(x \cdot x - 1 \cdot x\right)\right)\right)} \cdot \sqrt{1 + x}}\right)double f(double x) {
double r19023 = 2.0;
double r19024 = 1.0;
double r19025 = x;
double r19026 = r19024 - r19025;
double r19027 = r19024 + r19025;
double r19028 = r19026 / r19027;
double r19029 = sqrt(r19028);
double r19030 = atan(r19029);
double r19031 = r19023 * r19030;
return r19031;
}
double f(double x) {
double r19032 = 2.0;
double r19033 = 1.0;
double r19034 = r19033 * r19033;
double r19035 = x;
double r19036 = r19035 * r19035;
double r19037 = r19034 - r19036;
double r19038 = 3.0;
double r19039 = pow(r19034, r19038);
double r19040 = r19033 * r19035;
double r19041 = r19036 - r19040;
double r19042 = pow(r19041, r19038);
double r19043 = r19039 + r19042;
double r19044 = r19037 * r19043;
double r19045 = sqrt(r19044);
double r19046 = pow(r19033, r19038);
double r19047 = pow(r19035, r19038);
double r19048 = r19046 + r19047;
double r19049 = r19034 * r19034;
double r19050 = r19041 * r19041;
double r19051 = r19034 * r19041;
double r19052 = r19050 - r19051;
double r19053 = r19049 + r19052;
double r19054 = r19048 * r19053;
double r19055 = sqrt(r19054);
double r19056 = r19033 + r19035;
double r19057 = sqrt(r19056);
double r19058 = r19055 * r19057;
double r19059 = r19045 / r19058;
double r19060 = atan(r19059);
double r19061 = r19032 * r19060;
return r19061;
}



Bits error versus x
Results
Initial program 0.0
rmApplied flip3-+0.0
Applied associate-/r/0.0
rmApplied flip3-+0.0
Applied frac-times0.0
Applied sqrt-div0.0
rmApplied flip--0.0
Applied associate-*l/0.0
Applied sqrt-div0.0
Applied associate-/l/0.0
Final simplification0.0
herbie shell --seed 2020057
(FPCore (x)
:name "arccos"
:precision binary64
(* 2 (atan (sqrt (/ (- 1 x) (+ 1 x))))))