> [!NOTE] Definiton (Divergence) > Let $\underline{F}:U\subseteq \mathbb{R}^{3}\to \mathbb{R}^{3}$ be a [[Vector Field on Subset of Real n-Space|vector field]]. The *divergence* of $F$ is, denoted $\nabla \cdot F$ or $\text{div }\underline{F}$ is defined by $\text{div }\underline{F} = \left( \frac{ \partial }{ \partial x } , \frac{ \partial }{ \partial y } , \frac{ \partial }{ \partial z } \right) \cdot (\underline{F}_{x}, \underline{F}_{y},\underline{F}_{z}) = \frac{ \partial F_{x} }{ \partial x } + \frac{ \partial \underline{F}_{y} }{ \partial y } +\frac{ \partial \underline{F}_{z} }{ \partial z } $