In plane analytic geometry, the gradient is an increase in y corresponding to a unit increase in x. The gradient of a curve may be found at any point along it by use of differential calculus. Gradient is a vector quantity. In vector notation, the gradient of a scalar field W is the vector field


    grad W = iW/∂x + jW/∂y + kW/∂z


In other words, the gradient is a vector of partial derivatives of a function that operates on vectors.