Switch the divergence coordinate system

[oronanschel]

Homework Statement

i have the divergence in the (x,y,z) Cartesian as \frac{dA_x}{dx}+\frac{dA_y}{dy}+\frac{dA_z}{dz}

and the assignment is to transfer it to cylindrical system (r,{\phi},z), by any way i choose.

Homework Equations

tried with the chain rule, but i am doing something wrong, though
i get the gradient in the cylindrical system

 

[HallsofIvy]

It is impossible to tell you what, if anything, you are doing wrong if we cannot see what you did!

 

[oronanschel]

look at 1 then 2

then there is 1+2

in the left side there are some derivatives , and variables
transformation to explain