§@·~12

 
1.Construct a surface which appears as a triangle along the x-axis, 

appears as a triangle along the y-axis, 

apprears as an astroid along the z-axis 

and whose z-cross section are formed by ellipses. 



2.Construct a solid which appears as an equilateral triangle along the x-axis, 

appears as a half-ellipse along the y-axis, 

appears as a circle along the z-axis. 
                                                          



3.Construct the Klein bottle with parametric equations 
                              x = (a+cos(u/2) sin(v) - sin(u/2) sin(2v)) cos(u) 
                              y = (a+cos(u/2) sin(v) - sin(u/2) sin(2v)) sin(u) 
                                  z = sin(u/2) sin(v) + cos(u/2) sin(2v) 
4.Construct the hyperboloid of two sheets given by the equation 
                                          x2 - y2 - z2 = 1. 
5.Construct the smallest sphere that contains the six circles each of which is inscribed in a face of a cube. 
6.Construct the part of the sphere 
                                          x2 + y2 + z2 =1
lying outside the cylinder 
                                       (x - 0.5)2 + y2 = 0.25. 
7.Construct three tori of the same size each enclosing the other two. 
8.Show that a certain section of a cube consists of a hexagon. 
9.Construct the surface given by the equation 
                                     (x2 + y2 + z2)2 = 2z(x2+ y2) 
10.Construct the surface given by the   equation                       z=4-(xy)^(1/2)
                    (x2 + y2 + z2)2 = 2z(x2+ y2) 
11.Construct the same surface located above the disc 
                        x^2+y^2<=4                               
12.Construct the graph of the function     xy/(x^2+y^2)

as (x,y) ranges over the unit disc. 

13.Construct the solid enclosed by the paraboloids 
                                   z = 5x2 + 5y2 and z = 6 - 7x2 -y2.