\[\frac{r \cdot \sin b}{\color{red}{\cos \left(a + b\right)}} \leadsto \frac{r \cdot \sin b}{\color{blue}{\cos a \cdot \cos b - \sin a \cdot \sin b}}\]
0.2
Using strategy rm
0.2
Applied pow1 to get
\[\frac{r \cdot \sin b}{\cos a \cdot \cos b - \sin a \cdot \color{red}{\sin b}} \leadsto \frac{r \cdot \sin b}{\cos a \cdot \cos b - \sin a \cdot \color{blue}{{\left(\sin b\right)}^{1}}}\]
0.2
Applied pow1 to get
\[\frac{r \cdot \sin b}{\cos a \cdot \cos b - \color{red}{\sin a} \cdot {\left(\sin b\right)}^{1}} \leadsto \frac{r \cdot \sin b}{\cos a \cdot \cos b - \color{blue}{{\left(\sin a\right)}^{1}} \cdot {\left(\sin b\right)}^{1}}\]
0.2
Applied pow-prod-down to get
\[\frac{r \cdot \sin b}{\cos a \cdot \cos b - \color{red}{{\left(\sin a\right)}^{1} \cdot {\left(\sin b\right)}^{1}}} \leadsto \frac{r \cdot \sin b}{\cos a \cdot \cos b - \color{blue}{{\left(\sin a \cdot \sin b\right)}^{1}}}\]
0.3
Original test:
(lambda ((r default) (a default) (b default))
#:name "r*sin(b)/cos(a+b), A"
(/ (* r (sin b)) (cos (+ a b))))