\frac{r \cdot \sin b}{\cos \left(a + b\right)}
\frac{r \cdot \sin b}{\cos a \cdot \cos b - \sqrt[3]{\mathsf{expm1}\left(\mathsf{log1p}\left({\sin b}^{2} \cdot {\sin a}^{2}\right)\right) \cdot \left(\sin b \cdot \sin a\right)}}
(FPCore (r a b) :precision binary64 (/ (* r (sin b)) (cos (+ a b))))
(FPCore (r a b)
:precision binary64
(/
(* r (sin b))
(-
(* (cos a) (cos b))
(cbrt
(*
(expm1 (log1p (* (pow (sin b) 2.0) (pow (sin a) 2.0))))
(* (sin b) (sin a)))))))double code(double r, double a, double b) {
return (r * sin(b)) / cos(a + b);
}
double code(double r, double a, double b) {
return (r * sin(b)) / ((cos(a) * cos(b)) - cbrt(expm1(log1p(pow(sin(b), 2.0) * pow(sin(a), 2.0))) * (sin(b) * sin(a))));
}



Bits error versus r



Bits error versus a



Bits error versus b
Results
Initial program 14.7
Applied cos-sum_binary640.3
Applied add-cbrt-cube_binary640.4
Applied expm1-log1p-u_binary640.4
Simplified0.4
Final simplification0.4
herbie shell --seed 2021275
(FPCore (r a b)
:name "rsin A"
:precision binary64
(/ (* r (sin b)) (cos (+ a b))))