PX275 - C1b - divergence or div

\begin{matrix} \vec{\nabla} \cdot \vec{v} = [(\frac{\partial}{\partial x}) \hat{i} + (\frac{\partial}{\partial y}) \hat{j} + (\frac{\partial}{\partial z}) \hat{k}] \cdot [v_{x} \hat{i} + v_{y} \hat{j} + v_{z} \hat{k}] \\ ∴ \vec{\nabla} \cdot \vec{v} = \frac{\partial v_{x}}{\partial x} + \frac{\partial v_{y}}{\partial y} + \frac{\partial v_{z}}{\partial z} \end{matrix}

where, $\vec{v}$ is a vector field