¦^§@·~12

> restart;

> with(plots):with(plottools): 

Warning, the name changecoords has been redefined
> x1:=1;

x1 := 1

> y1:=cos(t);

y1 := cos(t)

> z1:=sin(t);

z1 := sin(t)

> z:=z1;

z := sin(t)

> x:=cos(s)*x1-sin(s)*y1;

x := cos(s)-sin(s)*cos(t)

> y:=sin(s)*x1+cos(s)*y1;

y := sin(s)+cos(s)*cos(t)

> u:=arctan(cos(t));

u := arctan(cos(t))

> a:=plot3d([x,y,z],s=0..Pi/2-2*u,t=-Pi/2..Pi/2,scaling=constrained):

> a;

[Maple Plot]

> b:=rotate(a,0,0,Pi/2):

> c:=display(a,b):

> c;

[Maple Plot]

> d:=rotate(c,0,0,Pi):

> e:=display(c,d):

> e;

[Maple Plot]

> vrml(e,"c:/042/12/12-5.wrl",background_color=white);

>