When the cone is placed steadily on the table on its base, (with the sphere inside it), the angle of elevation, measured from the centre of the base of the cone surface, to the centre of gravity in the sphere inside the cone is x degrees.
(a) show that volume of cone V = 1/3 (pi R^3 tan 2 x cotan^3 x
(b) show that mini volume of cone occurs at cos 2x = 1/3
(c) find the mini volume of the cone.
更新1:
(The angle of elevation x for the sphere's CG, is measured from the centre of gravity lying in this vertical line, the centre of the disk, and the other end of the flat disk.