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 r583075 = 2.0;
double r583076 = 1.0;
double r583077 = x;
double r583078 = r583076 - r583077;
double r583079 = r583076 + r583077;
double r583080 = r583078 / r583079;
double r583081 = sqrt(r583080);
double r583082 = atan(r583081);
double r583083 = r583075 * r583082;
return r583083;
}
double f(double x) {
double r583084 = 2.0;
double r583085 = 1.0;
double r583086 = x;
double r583087 = r583085 - r583086;
double r583088 = sqrt(r583087);
double r583089 = r583085 + r583086;
double r583090 = sqrt(r583089);
double r583091 = r583088 / r583090;
double r583092 = atan(r583091);
double r583093 = r583084 * r583092;
return r583093;
}



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