\cos^{-1} \left(\frac{1 - 5 \cdot \left(v \cdot v\right)}{v \cdot v - 1}\right)\frac{\pi}{2} - \sin^{-1} \left(\frac{1 - \left(\left(v \cdot v\right) \cdot 5\right) \cdot \left(\left(v \cdot v\right) \cdot 5\right)}{\left(v \cdot v - 1\right) \cdot \left(1 + \left(v \cdot v\right) \cdot 5\right)}\right)double f(double v) {
double r6655291 = 1.0;
double r6655292 = 5.0;
double r6655293 = v;
double r6655294 = r6655293 * r6655293;
double r6655295 = r6655292 * r6655294;
double r6655296 = r6655291 - r6655295;
double r6655297 = r6655294 - r6655291;
double r6655298 = r6655296 / r6655297;
double r6655299 = acos(r6655298);
return r6655299;
}
double f(double v) {
double r6655300 = atan2(1.0, 0.0);
double r6655301 = 2.0;
double r6655302 = r6655300 / r6655301;
double r6655303 = 1.0;
double r6655304 = v;
double r6655305 = r6655304 * r6655304;
double r6655306 = 5.0;
double r6655307 = r6655305 * r6655306;
double r6655308 = r6655307 * r6655307;
double r6655309 = r6655303 - r6655308;
double r6655310 = r6655305 - r6655303;
double r6655311 = r6655303 + r6655307;
double r6655312 = r6655310 * r6655311;
double r6655313 = r6655309 / r6655312;
double r6655314 = asin(r6655313);
double r6655315 = r6655302 - r6655314;
return r6655315;
}



Bits error versus v
Results
Initial program 0.5
rmApplied flip--0.6
Applied associate-/l/0.6
rmApplied acos-asin0.6
Final simplification0.6
herbie shell --seed 2019141
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 1"
(acos (/ (- 1 (* 5 (* v v))) (- (* v v) 1))))