Putting the two cylinders on the same plot

In order to put both cylinders on the same plot, we assign each plot to a name, say "p1" and "p2", and then use the "display" command to put both graphs on the same plot:

> p1:=implicitplot3d('x'^2+'y'^2=1,'x'=-1..1,'y'=-1..1,'z'=-0.5..2):

> p2:=plot3d('x'^2,'x'=-1.5..1.5,'y'=-1.5..1.5):

Notice the colon used at the end of these statements, rather than a semi-colon. This "suppresses the output" of the command. If you don't do this, you will see screenfulls of the internal details of the plot structure.

Now we can "display" the two plots:

> display({p1,p2},scaling=constrained,axes=frame,labels=['x','y','z']);

One can now see clearly what the spacecurve of intersection looks like. Let's plot it.

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