I should add that its divergence of A, meaning del dot A =0 . Also, I am aware of the other thread regarding this problem however that thread does not contain any useful information or attempt a solution.
Homework Statement
I need to show that $$\del*\vec{A(\vec{r})}=\frac{\mu}{4\pi}\int{\frac{\vec{J{vec\r'}}}{\vec{R}}}d\tau=0$$
where A is the vector potential and R refers to "script r" or (r-r') where r is source point of charge and r' is the measurement point. tau refers to a volume integral...