It’s been a long time since I’ve looked at coordinate systems and I’m struggling on a derivation in my research.
Suppose I have an equation of the form $r=r(\phi)$ which is just an azimuthal orbit. I need to find the normal vector to this orbit, how would I express this in terms of $\hat{r}$ and $\hat{\phi}$. I’ve been searching for ages and haven’t been able to find anything!
Thanks for your help