@Kitonum Thank you for informing me of Maple's ShowSolution command. It will come in handy for future explanations.

@Carl Love I find your hint of taking the log of both sides of y(x) to be a simpler (clearer) route to the final derivative than the steps given by Maple's Student aids.  

@Joe Riel Thanks for this advice.

@Carl Love Thanks to you (and the quite dense Maple help) I now have at least a rudimentary understanding of the meaning of specfunc and I now understand the output of my statements E, F and G.

And thank you for the hint of using applyop in place of subsop and for your kind offer of further help with any future question I may have in using specfunc.

@Carl Love Thank you. New Maple info always helps.

@vv Thank you once again for adding to both my Maple and math knowledge. 

BTW, the construction U^+ gives an " invalid power" error message in my Maple 2016. I changed this to Transpose(U).

@Carl Love I hope the uploaded worksheet is the kind of example you desire. If not I can copy and paste the code in a reply.

MinimalSurface.mw 

@Carl Love 

OnionExtended2.mw

@Carl Love I have reposted OnionExtended without the reference to my personal library and fully executed with plots inline rather than in windows. I hope you can access it. I'll also do this in future uploaded worksheets.

OnionExtended.mw

@Kitonum Your excellent replies and posts often inspire me to interesting modifications

OnionExtended.mw

@Kitonum in Maple 2016:-

with(combinat):

plot3d([op(permute([x, 1, y])[1 .. 3]), op(permute([x, 0, y])[1 .. 3])], x = 0 .. 1, y = 0 .. 1, color = [green, red, RGB(1, 0, 4), blue, grey, gold], style = surface)

@acer Your intimate knowledge of the internal workings of Maple in its various evolutions is both amazing and invaluable and I do enjoy your extended explanation.

Thank you for pursuing my query to its successful conclusion.

Perhaps this incident should convince me to buy each new year's edition of Maple!

@acer Thanks for your rapid reply. However in your worksheet the same error I originally encountered reappears when the explore command is executed, namely;

Error, (in type/satisfies) invalid input: type expects 2 arguments, but received 5

Clicking on this error message brings up a display of "There is no help for this error".

Is the error repeating because your worksheet is in a version of Maple later than my Maple 2016?

@tomleslie Here are renamed versions of the worksheets which you couldn't access. Good luck!

Worksheet2D.mw

Worksheet1D.mw

@tomleslie I converted the following worksheet from 2D to 1D math. Download_search.mw and Download_search2.mw failed to find the 2D version and found the 1D version.

Classical_Mechanics_13.15_surface_paths_geodesic_&_fastest_descent.mw

Classical_Mechanics_13.15_surface_paths_geodesic_&_fastest_descent_1D.mw

Almost all of my worksheets are written in 2D math. Is there any code in Maple which can find specific text within them?