2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)2 \cdot \tan^{-1} \left(\sqrt{\frac{1 - x}{1 + x}}\right)double f(double x) {
double r12107 = 2.0;
double r12108 = 1.0;
double r12109 = x;
double r12110 = r12108 - r12109;
double r12111 = r12108 + r12109;
double r12112 = r12110 / r12111;
double r12113 = sqrt(r12112);
double r12114 = atan(r12113);
double r12115 = r12107 * r12114;
return r12115;
}
double f(double x) {
double r12116 = 2.0;
double r12117 = 1.0;
double r12118 = x;
double r12119 = r12117 - r12118;
double r12120 = r12117 + r12118;
double r12121 = r12119 / r12120;
double r12122 = sqrt(r12121);
double r12123 = atan(r12122);
double r12124 = r12116 * r12123;
return r12124;
}



Bits error versus x
Results
Initial program 0.0
Final simplification0.0
herbie shell --seed 2020033
(FPCore (x)
:name "arccos"
:precision binary64
(* 2 (atan (sqrt (/ (- 1 x) (+ 1 x))))))