Initial program 15.1
\[\frac{r \cdot \sin b}{\cos \left(a + b\right)}\]
- Using strategy
rm Applied cos-sum0.3
\[\leadsto \frac{r \cdot \sin b}{\color{blue}{\cos a \cdot \cos b - \sin a \cdot \sin b}}\]
- Using strategy
rm Applied associate-/l*0.4
\[\leadsto \color{blue}{\frac{r}{\frac{\cos a \cdot \cos b - \sin a \cdot \sin b}{\sin b}}}\]
- Using strategy
rm Applied div-sub0.4
\[\leadsto \frac{r}{\color{blue}{\frac{\cos a \cdot \cos b}{\sin b} - \frac{\sin a \cdot \sin b}{\sin b}}}\]
- Using strategy
rm Applied *-un-lft-identity0.4
\[\leadsto \frac{r}{\frac{\cos a \cdot \cos b}{\color{blue}{1 \cdot \sin b}} - \frac{\sin a \cdot \sin b}{\sin b}}\]
Applied times-frac0.4
\[\leadsto \frac{r}{\color{blue}{\frac{\cos a}{1} \cdot \frac{\cos b}{\sin b}} - \frac{\sin a \cdot \sin b}{\sin b}}\]
Simplified0.4
\[\leadsto \frac{r}{\color{blue}{\cos a} \cdot \frac{\cos b}{\sin b} - \frac{\sin a \cdot \sin b}{\sin b}}\]
Final simplification0.4
\[\leadsto \frac{r}{\frac{\cos b}{\sin b} \cdot \cos a - \frac{\sin a \cdot \sin b}{\sin b}}\]