@dharr Thanks for your correction.

What I really want is Maple code which produces a display that duplicates figure 3.20 in my worksheet. My own effort is quite wide of the mark.

The book referred to in my worksheet contains several more intriguing pencil figures. I would also like to reproduce these if someone can show me a general technique for doing so.

@acer Although Rouben Rostamian has shown that there is no need to refer to plot3d's output, it was interesting to work with MESH.

@Rouben Rostamian  Your method is both simpler and more beautiful!

@ Thank you.

@nm I appreciate your help

@Carl Love Good advice. I will follow it.

@acer Thank you for this. I will avoid using concatenated names from now on.

@acer I was not aware of the power of rationalize, so thank you for showing this to me.

@Rouben Rostamian  The solution to Harvard problem 15 is interesting. I was not up to it myself, but I found it and copied it from some web site, though I've since lost that location's address.

@mmcdara I am impressed and astounded that a physics problem can be solved by a completely non-physics approach. Bully for you!

@Rouben Rostamian  Another great reply from you!

From an old list of Harvard weekly problems; with a given mass and a uniform density, this shape produces the greatest gravitational force at the origin.

@gkokovidis Based on djc561's recommendation above, I am exploring Micro-Cap at this time.

Depending on how I do, I may go on to explore your recommendation.

@djc I have installed Micro-Cap and begun to practice its capabilities by following Chapter 3 of the user manual.

I am deeply impressed by its sophistication, which is far above my needs. Hopefully I can become familiar enough with its simpler features to do simple circuit analysis.

Thank you very much for the reference

@tomleslie I'll do as you suggest.

@acer I would like to use a component featured circuit analyser but can't justify the cost of MapleSim.