Hello everyone.

Tell me how to solve this equation grad(div(f(x,y,z)))+K*Laplacian(f(x,y,z))=0

Here, the function f defines a vector field.

I tried so

Download eq.mw

Hello everyone. 

I can not calculate it here

Probably, the problem with the calculation of surface integrals. I would be grateful for any help.

Download 1.mw

Hello everyone. I have a few questions. For example, a tensor 1 and 2 ranks in some coordinate system. It is understood the equivalence 1 rank tensor and a vector. How to determine the flow and the divergence of the tensor. Maple is already in the package VectorCalculus command flux and divergence, as in the subpacket Vectors Physics package has a command divergence. But what about the tensors 2 and higher ranks? Is it possible to do these things a uniform manner? Under flow tensor mean surface integral of the scalar multiplication of the tensor of the 2nd rank in the normal vector, followed by contraction. My sketches in the attached file.

Flux_tensor_field.mw

Hello. Using a symbol ":", you can hide the derivation of the expression. However, it lost the label of expression. Can I hide the expression of retaining the label for further use? It would be handy when working with large expressions.

Hello. My question is in the attached file.

Question.mw