En enkel räking ger att \[ \textrm{rot} \, {\bf F}= \left| \begin{array}{ccc} e_x & e_y & e_z \\ \frac{\partial}{\partial x} & \frac{\partial}{\partial y} & \frac{\partial}{\partial z} \\ yz^2+y & xz^2 & 2xyz \end{array} \right| = \] \[ \left(\frac{\partial}{\partial y}\left(2xyz\right)- \frac{\partial}{\partial z}\left(xz^2\right), \frac{\partial}{\partial z}\left(yz^2+y\right)- \frac{\partial}{\partial x}\left(2xyz\right), \frac{\partial}{\partial x}\left(xz^2\right)- \frac{\partial}{\partial y}\left(yz^2+y\right) \right) \] \[ =(0,0,-1). \]