1. The problem statement, all variables and given/known data A vector field is defined by A=f(r)r a) show that f(r) = constant/r^3 if [tex]\nabla[/tex]. A = 0 b) show that [tex]\nabla[/tex]. A is always equal to zero 2. Relevant equations divergence and curl relations 3. The attempt at a solution I tried using spherical co-ordinates to solve this. But I am not sure if i am totally right.