in Maple 2025 on Linux, I see random Error, (in evala/Factors) the modular inverse does not exist from call to allvalues().

Sometimes it happens and sometimes not. Any explanation of this?

It seems Maple uses random number generatror to decide when to generate an internal error as I am not able to see a pattern.

Download why_fail_sometimes_may_11_2025_V2.mw

Update was able to produce this also in Maple 2024.2 on windows

Download modular_inverse_maple_2024_2.mw

Hi, I'm new to Maple.

when nesting some multiplications in a summation operator, I get results that I can't figure out.

I've entered 4 formulas that should give the same result, if I understood things correctly. The formula FB gives me problems; am I doing something wrong, or is there a bug in Maple? The problem arose in a more complicated formula, but I trimmed the formula down to a minimum, in order to illustrate the discrepancy.

I hope someone can shed some light on this, because I'm stuck.

Download BugTestSimple.mw

How do I find the solutions "links" with only answers in the range 0 to +1? The domain of vgl is 0 <=beta <= 1. If the system is inconsistent or insufficient to solve xi (for example, if xi does not appear in the equation) then give the text "no solution". If there is a solution then show it. Filter only real solutions. Please help me with better code:

restart;
assume(beta > 0, beta < 1):
interface(showassumed=0):

vgl[1] := -((beta*xi^2 + 2*xi^2 - beta)*(beta - 1)^2)/4 = 0:  # or some other equation (sometimes xi does not appear in the equation)

if has(lhs(vgl[1]), xi) or has(rhs(vgl[1]), xi) then
    links := solve([vgl[1], xi > 0, xi < beta], xi):
    # Filter only real solutions
    links_real := select(x -> type(x, equation) and is(Im(rhs(x)) = 0), [links]):
    if nops(links_real) > 0 then
        x1 := links_real;
        print("Real solution(s):", x1);
    else
        print("No real solution in range for xi.");
    end if;
else
    print("The equation does not contain xi — solving for xi is not possible.");
end if;
 

I would like to automatically select a set of parameters that gives me a "good" solution, ideally, one where not all parameters are zero. The parameters A[0], A[1], A[2], B[1], and B[2] are essential and must always be included. The other parameters are optional and can be selected in various combinations (e.g., one, two, or more at a time).

Currently, I manually add or remove these optional parameters, which is time-consuming. I’m looking for a way to automate the selection process to find the best combination of parameters that yields a valid and meaningful (non-zero) solution.

How can I approach this systematically?

params.mw

Download params.mw

is it possible to ask Maple to verify ode solution obtained from book, which is given in parametric form to check if it is correct?

I know odetest supports both explicit and implicit solutions. But parametric solution is neither of these.

The solution in parametric form makes it look simple to look at and understand, but at same time, not practical in terms of obtaining an explicit solution to verify it and to use it.

The book "handbook of exact solution for ordinary differential equations" by Polyanin and Zaitsev have many such solutions.

Here is one such example of many

I can not just give odetest the y(x) solution above, because the right side depends on tau, which is parameter. If I try to solve for tau in terms of x from the first equation it will become so complicated and odetest hangs. So a whole new different approach is needed as brute force method is not practical in most cases.

Download how_to_verify_parametric_solution_to_ode.mw

Some more examples from the book where solutions are given only in parametrric form

update

inspired by solution below by @acer, I found if I just use Solve on the x equation, in order to find t as function of x, and use that in the y equation, it will automatically return solution using RootOf.

Hence no need to explicitly evaluate the integral or explicity set up the RootOf manually.

Now odetest work. 

Download how_to_verify_parametric_solution_to_ode_V2.mw

i seperate my equation of real part and imaginary part i want  after taking integrale from my real part we see the pattern betwen real and imaginary part  which they equal about variable beside coefficient , i want to determine and find parameter from real part of my equation then substitute in imaginary for solving but  the number of condition i don't know is how much and there is a little bit repeatation how i can determine the correct one and then substitute ?

Download F-condition_and_replacing.mw

I am not sure how to use dsolve for my problem.
CQ_v1.mw

Hi everyone, I am trying to plot graphs for dp/dx versus x from my ordinary differential equation numerically. My file is working, but the outcome is straight lines, which means I am doing something wrong. Could anyone  please have a look on my file.

Help-dpdx.mw

the expected  results should be  look like this

Is there a trick to make Maple simplify 

to

I can't use the exp() trick given in earlier questions, since there is no exp here. Below are my attempts. Can someone find another smart trick to do this simplification? Should simplify() have simplified it as is with no assumptions or using tricks? This is all done in code, so solutions can not depend on "looking on screen" and deciding what to do for each step.

Download simplification_may_8_2025.mw

For reference, using another software

I'm trying to extract the real and imaginary parts of a given PDE. However, during the substitution step, something unexpected occurs. Specifically, my replacement does not yield the expected result, and an extra term appears: D(k)(t*w + x) in the expression P11. I'm unsure why this term arises and would appreciate any insight into what might be going wrong during the substitution process.

Download tr.mw

I do not remember seeing this before or reporting. Just in case, here is how to reproduce it. This happens also in Maple 2024.2

The problem with these errors is that they can not be cought using try/catch.

I was testing a solution which most likely wrong, but I get 

                 Error, (in content/gcd) too many levels of recursion

Download content_gce_odetest_error_may_7_2025.mw

I asked similar question 5 years ago about Physics update but it was not possible to find this information

How-To-Find-What-Changed-In-Physics

I'd like to ask now again same about  SupportTools. Can one find out what update is actually included in new version?

Even if it is just 2-3 lines. It will be good if users had an idea what was fixed or improved in the new version.

Any update to software should inlcude such information. Not asking for details, just general information will be nice. Right now one does an update and have no idea at all what the new update fixed or improved which is not good.

May be such information can be displayed on screen after a user updates?

I want to convert my code output into LaTeX format, but the current formatting isn't suitable for presentation. For example, when I use simplify, it sometimes introduces unnecessary fractions, making the expression look cluttered and less elegant on paper. I'm looking for a way to simplify expressions preferably by factoring terms, without introducing extra fractions, so the final LaTeX result appears clean and well-structured.

Download B-R.mw

How can we eliminate nonlinear terms involving two functions in a differential equation?

Download remove.mw

Hi!

Sorry if I am missing something or not following any implicit rules, I am really new to Maple and this forum.

For the sake of completeness, here the code that is given:

Ve := Vector([VeX, VeY, VeZ]);
with(LinearAlgebra);
Vh := Normalize(Vector([alphaX*Ve(1), alphaY*Ve(2), Ve(3)]), Euclidean, conjugate = false);
lensq := Vh(1)*Vh(1) + Vh(2)*Vh(2);
T1 := Vector([-Vh(2), Vh(1), 0])/sqrt(lensq);
T2 := CrossProduct(Vh, T1);
r := sqrt(x);
phi := 2*Pi*y;
t1 := r*cos(phi);
t2 := r*sin(phi);
s := 1/2*(1 + Vh(3));
t22 := (1 - s)*sqrt(1 - t1*t1) + s*t2;
Nh := t1*T1 + t22*T2 + sqrt(1 - t1*t1 - t22*t22)*Vh;
NULL;
Ne := Normalize(Vector([alphaX*Nh(1), alphaY*Nh(2), Nh(3)]), Euclidean, conjugate = false);
AV := (-1 + sqrt(1 + (alphaX^2*Ve(1)^2 + alphaY^2*Ve(2)^2)/Ve(3)^2))/2;
G1 := 1/(1 + AV);
DN := 1/(Pi*alphaX*alphaY*(Ne(1)^2/alphaX^2 + Ne(2)^2/alphaY^2 + Ne(3)^2)^2);

DVN := G1*DotProduct(Ve, Ne, conjugate = false)*DN/DotProduct(Ve, Vector([0, 0, 1]), conjugate = false);
PDF := DVN/(4*DotProduct(Ve, Ne, conjugate = false));

So far, so good. Now what I want to do is:

PDFint := int(PDF, [x = xInf .. xSup, y = yInf .. ySup]);

to calculate the symbolic integral of PDF over x and y. The issue is that I keep running out of memory after a few hours and my operating system (Linux Fedora) automatically shuts Maple down.

I am convinced that there must be a way to either preprocess PDF so that the int(...) command doesn't eat up all the RAM, or some different way to calculate an integral that maybe has a different structure?

I have tried codegen[optimize](PDF) and liked what it did, but I don't know how to progress with the result of it, if at all possible.

I know that there is also a way to calculate the integral numerically, but I need the analytic integral, so numerical solutions are of no use to me.

If there is really no way for me to obtain this integral, I would really appreciate an explanation of why, so that I can rest at night finally lol.

Thank you in advance,

Jane