a) Express the two points of intersection that are not the origin of the two curves r=4(1+sin) and r=4(1cos) given in polar coordinates in polar coordinates. And find the distance between the two vertices.

b) In the Cartesian coordinate system, express the area formed by the common part of the cone x^2 + y^2 2(z^2) and the sphere x^2 + y^2 + z^2 1z in spherical coordinates.