Let $\mathbf { r } = x \mathbf { i } + y \mathbf { j } + z \mathbf { k }$

Short Answer

Let $\mathbf { r } = x \mathbf { i } + y \mathbf { j } + z \mathbf { k }$ and $r = | \mathbf { r } |$ .
Find $\nabla \cdot ( \mathbf { r } )$