> restart:

> with(plots):

Warning, the name changecoords has been redefined

> a:=tubeplot([cos(t),0,sin(t)],t=0..2*Pi,scaling=constrained,radius=0.3,
grid=[30,10],lightmodel=light3):

>

> b:=tubeplot([1+cos(t),sin(t),0],t=0..2*Pi,scaling=constrained,radius=0.3,
grid=[30,10],lightmodel=light1,title="87121 By J.S.C."):

>

> display(a,b);