@Muhammad Usman You assign to f the result from plots:-surfdata, and then pass that f as the first argument to plots:-densityplot.

What do you expect that to do?

You should describe what you're actually trying to do, in adequate detail. I can't help you, if you don't.

What version of Maple are you using? Is it still Maple 2015?

Please put close followup queries to this here, instead of spawning wholly separate new Question threads for such.

@C_R I started with the Help page ?dsolve,numeric,DAE because in your Question you showed that the call came from the example worksheet for ?examples,numeric_DAE.

ps. If I enter the following in the Google search bar of my Chromium web-browser then the first hit is to that ?dsolve,numeric,DAE Help page.
    maple help dsolve "differential option"

I'm merely reporting what worked for me. Searching is often tricky.

@Traruh Synred Your boostTo.mw attachment here was saved using Maple 2018.2 (released in the year 2018), and not Maple 18 (released in the year 2014).

The naming scheme was changed in 2015, to have the release number match the year.

@Traruh Synred Your dMemB1List and dMemB2List are rtables (eg. Arrays, or row Vectors), and not lists.

You could try and concatenate them with,

   <dMemB1List|dMemB2List>

Your worksheet is missing code that defines B_recursive.

@Rouben Rostamian  This is nicely explained. Vote up.

If I'm not mistaken, a savings in the size of the constructed plot structure can be had by using a value of 2 for the first entry of the grid option, eg, grid=[2,49]. (The default value is 49.)

mw_3_ac.mw

@zenterix It seems that you haven't understood what I wrote about calling value.

The name R occurs inside the inert call %log[10](R), so you can turn that into its active call and then solve it by,
    solve(value(expr), R)

An inert call (preceded by %) is inactive, like a placeholder. From the Help page for the value command, "During computations, inert functions remain unevaluated (the operations they represent remain unperformed)."

What are your initial conditions?

Your equation appears to be missing a multiplication symbol * between n and the left opening backet beside it.

There is no special mechanism to allow multiple people to edit the same .mw file at the same time.

@C_R In terms of students, and demonstrating proofs, if might be fun to code up some of these.

One tricky aspect is that I'd prefer to be able to apply such single-steps to subexpressions of a current line in a running proof. That'd make it more textbook-like. Yet usual context-menus are not so convenient for subexpression conversions; one way to mimic it is to populate a context-menu's submenu, on-the-fly, populated with precomputed replacements determined with much type-checking/matching. (There is also a right-panel subexpression menu thingy, which can do subexpression replacements, in-situ, but is not really user-extensible.) It would not be such quick fun to code it up as a Tutor.

Regular context-menu extensions can be put reasonably easily into the ModuleLoad of a package module, eg. like L.

@dharr Just because it might be of interest to the OP...

Download A1_ac.mw

@C_R The small module L may be augmented to rebind lhs and rhs as well.

Logic_2DInput_lrhs.mw

(You could also guard against incorrect number of arguments, if you'd prefer some customized error message, etc.)

What exactly are you hoping to construct using the plot3d command? Please be clear.