The gradient of a

function is a

vector pointing in the

direction of most

rapid ascent or

descent. It is

represented by the

character del. To find the gradient of a function f, take:

del f = df/dx **a**_{x} + df/dy **a**_{y} + df/dz **a**_{z}

Where all derivatives are actually partial derivatives, and all vectors **a** are unit vectors pointing in the denoted directions.