8-10 Construct knots as thus:

> restart;

> with(plots):with(plottools):

Warning, the name changecoords has been redefined

> r:=3+cos(s/5):x:=r*cos(s):y:=r*sin(s):z:=sin(s/5):

> p:=tubeplot([x,y,z],s=0..10*Pi,radius=0.3,grid=[100,10],scaling=constrained):

> p;

> vrml(p,"c:/Program Files/Maple 6/beauty/8-10.wrl",background_color=white);

>