Unless I'm missing something where are the closed integral symbols? 

I couldn't find them but you can create them if you wanted to.  Then I tried adding them to a palette with DocumentTools and couldn't get it to work. 

`∮` `∯` `∰`
                                                        

Creating the double and triple symbols can be done  easily by concatenating as many ∫  as you desire. But can't seem to add them to a palette.

DocumentTools:-AddPalette("Integral Symbols");

AddIcon("Closed Integral",`∮`)

I suppose you need to create a png file for that to work.  However the above would be simpler.

Maybe add functional closed integral operator symbols for the palette? 

how can i factor from 0.03 in this equation and show like the yellow equation

f := 0.03 - 0.03*cos(5.885*t)

restart;
with(LinearAlgebra):

l_1 := diff(x1(t), t) = 1/2*x1(t) - x2(t) + cos(4*t);
                 d          1                         
         l_1 := --- x1(t) = - x1(t) - x2(t) + cos(4 t)
                 dt         2                         

l_2 := diff(x2(t), t) = 3/2*x1(t) - 2*x2(t) - 1;
                    d          3                    
            l_2 := --- x2(t) = - x1(t) - 2 x2(t) - 1
                    dt         2                    

dsolve({l_1, l_2}, {x1(t), x2(t)});
    /          4               296              28          
   { x1(t) = - - exp(-t) _C1 + ---- sin(4 t) - ---- cos(4 t)
    \          3               1105            1105         

           /  1  \                                    
      + exp|- - t| _C2 + 2, x2(t) = -2 exp(-t) _C1 + 1
           \  2  /                                    

         93              36                /  1  \    \ 
      - ---- cos(4 t) + ---- sin(4 t) + exp|- - t| _C2 }
        1105            1105               \  2  /    / 

A := <<1/2 | -1>, <3/2 | -2>>;
                           [1            ]
                           [-  &uminus0;1]
                           [2            ]
                      A := [             ]
                           [3            ]
                           [-  &uminus0;2]
                           [2            ]

Eigenvectors(A, output = list);
              [                  [        /[2]\ ]]
              [[-1      /[1]\ ]  [        |[-]| ]]
              [[--, 1, { [ ] }], [-1, 1, < [3] >]]
              [[2       \[1]/ ]  [        |[ ]| ]]
              [                  [        \[1]/ ]]

NULL;

I assume, I am getting a result in the format of:

Which implies, that the eigenvalues from dsolve are -1/2 and -1, which are correct according to the eigenvalues gotten from the matrix A.

But the eigenvector for the eigenvalue -1/2 appears to be incorretly given by dsolve, I should get 2/3 and no -4/3 in the top axis of the V_lambda(-1). For the second row I am getting -2 and not 1. It appears that Maple has multiplied the eigenvector for the eigenvalue -1 with -2? Or am I missing something?

If I am not missing anything; what appears to cause this issue?

How to get a general expression here ?

Download Maple_primes_bvraag_hoger_orde_singulariteit_henk_hofstede.mw

I do not understand why what I do in my first example does not work in the problem of integral. Can anyone help me? Thank you very much!

Download First_example_Maple.mw

Download Problem_of_integral.mw

This worksheet has an error when executing EulerLagrange.

How can this error be avoided?

Spring_Pendulum.mw

As a Maple user for 10+ years, I've had plenty of stack limit errors, pretty much all of them my fault. But I am currently experiencing a very unusual one after updating my Mac from Maple 2019 to Maple 2021.2.

I am running a long script to fetch json data from a url, parse it, and do a bunch of analysis. In most cases it works fine, but some cases give either an "Execution stopped: Stack limit reached." error, or the error "Error, (in type/polynom) result from type `algfun` must be true or false". Both are being caused by calling the gfun:-ratpolytocoeff command.

I kind of think some internal memory of Maple is being accidentally overwritten because I can cause the error to occur or not occur by adding / commenting out random lines of code that have nothing to do with the part of the code causing the problem. I've managed to find a fairly small script that causes the problem to occur:

with(PolynomialIdeals):
url := "https://api.combopal.ru.is/garpur_run/61e5f7acf2e929ff811caad3":

root_func := F[0, x]:

latex:-Settings(useimaginaryunit=i):

data := URL[Get](url):
json := JSON[ParseString](data):
json := JSON[ParseString](data):

debug_solved := (x^5-3*x^4+5*x^3-7*x^2+4*x-1)/(x^5-5*x^4+10*x^3-10*x^2+5*x-1):

debug_gfun := gfun[ratpolytocoeff](debug_solved, x, n);

If I remove ANY of these lines of code, there is no longer any problem, which is very strange because, for example, I'm not using the PolynomialIdeals package anywhere in the script. This particular script works fine on a Linux machine running 2021.0, but yet I am having similar problems on that machine with other cases.

Here's a slightly simpler example in which gfun[ratpolytocoeff] induces a "division by zero" error ("Error, (in convert/fullparfrac/normal_only) numeric exception: division by zero"):

with(PolynomialIdeals):
url := "https://api.combopal.ru.is/garpur_run/61e5f7acf2e929ff811caad3":

latex:-Settings(useimaginaryunit=i):

data := URL[Get](url):
json := JSON[ParseString](data):
json := JSON[ParseString](data):

debug_gfun := gfun[ratpolytocoeff](1/(1-x), x, n);

After the division by zero error, if I press Ctrl+D to close the Maple command line, it prints
"GC Thread signalAbort 0x7000019a5000 Execution stopped: Stack limit reached.".

Is this an internal Maple bug? Is there any workaround? I am pulling my hair out and would be very grateful for any help.

psi := psi(t)

psi := psi(t);
Error, recursive assignment
How can this assignment be accomplished?

There seems to be a bug in Maple 2021, latest release. Not sure if this was in previous versions.

When checking off the "Show Column Header" in Datatables, the cells are becoming invisible, while the column header still remains.

Show Row Header on the other side works fine.

A user wondered how to have Maple produce a desired form of a solution

Download question-better-spacing.mw

We suggested the closest they might be able to get is using simplify like so:

Download suggestion.mw

Hi, I would be grateful if anyone could help find inconsistency in a system of equations I have been solving. I can easily solve the system (that I have called ‘EQs’) when I set the parameter ‘tau\_l’ equal to .06, but for a different value, it will not solve. The same thing happens whenever I change the value of some other parameters like ‘l3’. Regards

ACCOLLEY_Delali_-_Demographics_3.mw

Hello guys,

I want to find exact form of a(t) in following differential equation:

-diff(a(t), t)^2*_C1*6^(-1/(-1 + 2*alpha))*((diff(a(t), t, t)*a(t) + diff(a(t), t)^2)/a(t)^2)^(-1/(-1 + 2*alpha))/(4*(diff(a(t), t, t)*a(t) + diff(a(t), t)^2)*(-1/2 + alpha)) = (6*diff(a(t), t, t)*a(t)^2*alpha + 6*a(t)*diff(a(t), t)^2*alpha + k^2)/a(t)^3

please guide me,

I am looking for something like the equal sign (“=”) with a question mark (“?”) on top.

This would be handy to express an unknown relation or something that has to be proofed.

If not: Is it possible to create custom symbols?

Many times when using the debugger, and hitting the NEXT button I get the message

   Warning, cannot determine statement number; procedure may have changed in-place

The problem is that after this, hitting NEXT will not go to next statement any more. It will bypass and return from the current procedure. but hitting STEP will make it go to next statement, But STEP will also go into next block which I might not want to do.

Only way to fix this is to terminate the debugging session and start all over again.

it is random and comes up in different places. The code in in .mla file and I step through it.

I am sure anyone who have used the buildin debugger have seen this message before. It shows for me many times. 

What causes it and what can one do to not make it show up or clear it up so one does not have to restart the debugging each time it shows up?

Here is a screen shot.  I am also wondering if this happens using the emacs interface to the Maple debugger? I have not used the emacs interface to the debugger before.

Maple 2021.2 on windows 10