r \cdot \frac{\sin b}{\cos \left(a + b\right)}r \cdot \left(\sin b \cdot \frac{1}{\cos a \cdot \cos b - \sin a \cdot \sin b}\right)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) * (1.0 / ((cos(a) * cos(b)) - (sin(a) * sin(b))))));
}



Bits error versus r



Bits error versus a



Bits error versus b
Results
Initial program 15.5
rmApplied cos-sum0.3
rmApplied div-inv0.4
Final simplification0.4
herbie shell --seed 2020102
(FPCore (r a b)
:name "r*sin(b)/cos(a+b), B"
:precision binary64
(* r (/ (sin b) (cos (+ a b)))))