gradient

Gradient of a multivariate function at a point is a vector pointing at the direction of steepest increase in value, with a magnitude of the function’s directional derivative in the pointed direction. each partial derivative. Its components consist of partial derivatives of the corresponding variables. For instance, $\nabla f(x,y,z)=\frac{\partial f}{\partial x}\mathbf{i}+\frac{\partial f}{\partial y}\mathbf{j}+\frac{\partial f}{\partial z}\mathbf{k}$