Coordenadas esféricas

$\displaystyle \hat{r}$	$\textstyle =$	$\displaystyle \hat{x} \, {\rm sen} \phi \, {\rm cos} \theta \, + \, \hat{y} \, {\rm sen} \phi \, {\rm sen} \theta \, + \, \hat{z} \, {\rm cos} \phi$
$\displaystyle \hat{\theta}$	$\textstyle =$	$\displaystyle - \hat{x} \, {\rm sen} \theta \, + \, \hat{y} \, {\rm cos} \theta... ...ypurple}\left[ \, = \, \frac{d \, \hat{r}}{d \theta} (\phi = \pi/2) \, \right]}$
$\displaystyle \hat{\phi}$	$\textstyle =$	$\displaystyle \hat{x} \, {\rm cos} \phi \, {\rm cos} \theta \, + \, \hat{y} \, ... ...i \quad {\color{mypurple}\left[ \, = \, \frac{d \, \hat{r}}{d \phi} \, \right]}$