In summary, the conversation discusses a problem involving proving a relation in cartesian coordinates using integration by parts and the given hint of using the fact that $d\vec{r} = dx\,dy\,dz$ in a volume integral. The conversation also touches on the use of the del symbol and the Einstein summation convention. The conversation ultimately suggests approaching the problem by writing out the integrals in terms of known concepts and applying integration by parts to each term separately. There is also a discussion about the correct notation and understanding of integration by parts.
#36
jhartc90
43
0
What sort of BCs? Just as r->infinity, f(r)A(r) goes to 0?