# Math Help - Polar coordinates

1. ## Polar coordinates

hi, i need help with this question

using speherical polar coordinates $(r,\theta, \phi)$
verify that the vector $F =r^-2e_r$ is solenoidal i.e. $\nabla \wedge F =0$, how do i express $F$ in vector form, and how do i go about answering this question

2. Originally Posted by iLikeMaths
hi, i need help with this question

using speherical polar coordinates $(r,\theta, \phi)$
verify that the vector $F =r^-2e_r$ is solenoidal i.e. $\nabla \wedge F =0$, how do i express $F$ in vector form, and how do i go about answering this question
F is already in vector form. $e_r$ is the radial unit vector ......

Go to your formula for the cross product in spherical coordinates and substitute the component of F. You should get the 0 vector as the answer.