\frac{r \cdot \sin b}{\cos \left(a + b\right)}\sin b \cdot \frac{r}{\cos b \cdot \cos a - \sin b \cdot \sin a}(FPCore (r a b) :precision binary64 (/ (* r (sin b)) (cos (+ a b))))
(FPCore (r a b) :precision binary64 (* (sin b) (/ r (- (* (cos b) (cos a)) (* (sin b) (sin a))))))
double code(double r, double a, double b) {
return (((double) (r * ((double) sin(b)))) / ((double) cos(((double) (a + b)))));
}
double code(double r, double a, double b) {
return ((double) (((double) sin(b)) * (r / ((double) (((double) (((double) cos(b)) * ((double) cos(a)))) - ((double) (((double) sin(b)) * ((double) sin(a)))))))));
}



Bits error versus r



Bits error versus a



Bits error versus b
Results
Initial program 15.1
Simplified15.1
rmApplied cos-sum0.3
rmApplied associate-*r/0.3
Simplified0.3
rmApplied *-un-lft-identity0.3
Applied times-frac0.3
Simplified0.3
Final simplification0.3
herbie shell --seed 2020198
(FPCore (r a b)
:name "rsin A"
:precision binary64
(/ (* r (sin b)) (cos (+ a b))))