Chapter 14.5, Problem 17E

Divergence of radial fields Calculate the divergence of the following radial fields. Express the result in terms of the position vector r and its length |r|. Check for agreement with Theorem 14.8.

17.     $F=\frac{\left(x,y,z\right)}{x^2+y^2+z^2}=\frac{r}{{\left|r\right|}^2}$