\[\frac{r \cdot \sin b}{\color{red}{\cos \left(a + b\right)}} \leadsto \frac{r \cdot \sin b}{\color{blue}{\cos a \cdot \cos b - \sin a \cdot \sin b}}\]
0.3
Using strategy rm
0.3
Applied pow1 to get
\[\frac{r \cdot \sin b}{\color{red}{\cos a \cdot \cos b - \sin a \cdot \sin b}} \leadsto \frac{r \cdot \sin b}{\color{blue}{{\left(\cos a \cdot \cos b - \sin a \cdot \sin b\right)}^{1}}}\]
0.3
Removed slow pow expressions
Original test:
(lambda ((r default) (a default) (b default))
#:name "r*sin(b)/cos(a+b), A"
(/ (* r (sin b)) (cos (+ a b))))