Translations:The gradient/2/es

${\begin{aligned}\mathrm {grad} {\textit {t}}&{\rm {=}}\left({\frac {\partial t}{\partial x}}{\rm {,\ }}{\frac {\partial t}{\partial y}}\right){\rm {=}}{\frac {\partial t}{\partial x}}\mathbf {i} +{\frac {\partial t}{\partial y}}\mathbf {j} .\end{aligned}}$

(4)