Hint: The equation x2+y2+z2=1 is the equation of the sphere in R3 of radius 1 centred at the origin. The condition z≥0 gives you the upper hemisphere, ... ... <看更多>
Definition : A 1-form is a linear function which sends every vector to a scalar. Define dx to be the 1-form which acts on a vector (x, y, z) by ... ... <看更多>
