\cos^{-1} \left(\frac{1 - 5 \cdot \left(v \cdot v\right)}{v \cdot v - 1}\right){\left(e^{\sqrt[3]{\sqrt{\log \left(\cos^{-1} \left(4 \cdot \left({v}^{2} + {v}^{4}\right) - 1\right)\right)}} \cdot \sqrt[3]{\sqrt{\log \left(\cos^{-1} \left(4 \cdot \left({v}^{2} + {v}^{4}\right) - 1\right)\right)}}}\right)}^{\left(\sqrt[3]{\sqrt{\log \left(\cos^{-1} \left(4 \cdot \left({v}^{2} + {v}^{4}\right) - 1\right)\right)}} \cdot \sqrt{\log \left(\cos^{-1} \left(4 \cdot \left({v}^{2} + {v}^{4}\right) - 1\right)\right)}\right)}double code(double v) {
return ((double) acos(((double) (((double) (1.0 - ((double) (5.0 * ((double) (v * v)))))) / ((double) (((double) (v * v)) - 1.0))))));
}
double code(double v) {
return ((double) pow(((double) exp(((double) (((double) cbrt(((double) sqrt(((double) log(((double) acos(((double) (((double) (4.0 * ((double) (((double) pow(v, 2.0)) + ((double) pow(v, 4.0)))))) - 1.0)))))))))) * ((double) cbrt(((double) sqrt(((double) log(((double) acos(((double) (((double) (4.0 * ((double) (((double) pow(v, 2.0)) + ((double) pow(v, 4.0)))))) - 1.0)))))))))))))), ((double) (((double) cbrt(((double) sqrt(((double) log(((double) acos(((double) (((double) (4.0 * ((double) (((double) pow(v, 2.0)) + ((double) pow(v, 4.0)))))) - 1.0)))))))))) * ((double) sqrt(((double) log(((double) acos(((double) (((double) (4.0 * ((double) (((double) pow(v, 2.0)) + ((double) pow(v, 4.0)))))) - 1.0))))))))))));
}



Bits error versus v
Results
Initial program 0.6
Taylor expanded around 0 0.7
Simplified0.7
rmApplied add-exp-log0.7
rmApplied add-sqr-sqrt0.7
Applied exp-prod0.7
rmApplied add-cube-cbrt0.7
Applied exp-prod0.7
Applied pow-pow0.7
Final simplification0.7
herbie shell --seed 2020120
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 1"
:precision binary64
(acos (/ (- 1 (* 5 (* v v))) (- (* v v) 1))))