Folks,

I need to show that \nabla \times (f F)= f \nabla \times F+ (\nabla f) \times F

How will I represent the scalar function? Do I write f=\psi(x,y,z) or

f=A_x+A_y+A_z

I chose F=a_x \vec i +a_y \vec j +a_z \vec k

Using f=\psi(x,y,z) I work out the LHS of question as

(\psi a_z)_y-(\psi a_y)_z-(\psi a_z)_x+(\psi a_x)_z+(\psi a_y)_x-(\psi a_x)_y.............How to go further?

Thanks