The worksheet below displays dual cones inside the unit sphere, but the Gauss-Bonnet formula (area of upper cone's spherical cap plus length of dual cone's intersection with unit sphere) does not equal 2*Pi.

Please find my error.

Dual_cones.mw

When executing DEBUG within inline code (not within a procedure) the values displayed in successive debug windows (on clicking continue) are added to the end of my worksheet. How can the latter display be prevented?

The sphere with radius 0.5 whose center has y coordinate = 0.5 and z coordinate = 0.5 is tangent internally to the ellipsoid centered on the origin with principal semi axes of 5, 3 and 2.

How can the x coordinate of the sphere's center be determined?

Imagine a brachistochrone shaped path made of a frictionless flexible metal strip which reacts to the force of a weighty sliding object.

Depending on its flexibility and the object's mass, what would be the strip's initial shape for fastest descent between its top and bottom? How would its shape change during the object's descent?

Perhaps an aircraft emergency escape slide or the fastest path for a slalom skier exemplify this kind of situation.

A flexible rope of constant linear density hangs from one fixed end.

The lower end is pulled aside and then released.

The rope swings back and forth with a whip-like action.

What equation of motion can be used to animate this action in Maple?

I cannot find any references through Google to the appropriate math.