In the final plot in this worksheet, the electric field is displayed using blue headless vectors.

Instead, how can the gradient of the dipole's potential field be displayed in field lines?

Dipole_fields.mw

Circular_gears_meshing_blunt_teeth_shape_from_involute_of_circle.mw

My worksheet has suddenly begun producing the following error message when executing legitimate commands:

Error, (in cos) type `SymbolicInfinity` does not exist

Why has this worksheet suddenly begun issuing these mysterious error messages and how can it be restored to working order?

The uploaded worksheet is intended to be an example of the Equal Incircles Theorem, but the incircles displayed are not equal.

What is wrong in the worksheet and how can the error(s) be corrected?

Equal_Incircles_theorem.mw

I am particularly interested in a full coordplot3d display for ellipsoidal coords. 

This worksheet animates the motion of an object (say, a cube which slides frictionlessly) on a rotating carousel. The cube is not self-propelled.

How can the worksheet be modified to handle the combination of the carousel motivated motion and the cube's own generated motion, caused by, say, by a few strategically placed thrusters?

The cube's own generated path could be a straight line, or a curve such as an ellipse. The cube's own motion could have a constant velocity or be accelerating.

Carousel_dynamics.mw