I have a problem with divergence function DIV in DERIVE 6.1 and canot find anything in help and web forums either.
#1. At first, I load utility "VectorMatrixFunctions.mth"
#2. when I insert DIV([1/r^2, 0, 0], spherical) I obtain ZERO
But it seems wrong,
f.e. for Gravitation we have divergence for vectors with (1/r^2) and we should expect poisson equation related to volume,
As we know for gravity it is (4 \pi GMm ) / V
What is wrong then with my calculations using Derive 6?