作業九

9-1	Construct the sphere with the command "plot3d".
9-2	Construct the sphere with this pattern:
9-3	Construct the sphere with this pattern:
9-4	Construct the sphere with this pattern:
9-5	Construct the part of the cylinder (x - 0.5)2 + y2 = 0.25 lying inside the sphere x2 + y2 + z2 =1.
9-6	Construct the intersection of the cylinder (x - 0.5)2 + y2 = 0.25 and the sphere x2 + y2 + z2 =1.
9-7	Construct the sphere with the command "sphere" in "plottools".
9-8	Construct eight spheres of the same size each touching three others.
9-9	Construct four mutually tangent spheres of the same size:
9-10	Construct six spheres of the same size each touching four others
9-11	Construct twelve spheres of the same size each touching five others