Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

Hello everyone,

I am working on reproducing Fig. 12 (Isotherms) and Fig. 13 (Streamlines) from the attached paper, cacity_paper_work.pdf which deals with natural convection of GO–MgO/silicone oil hybrid nanofluid inside square and H-shaped cavities under a periodic magnetic field.

Equations (9–11) in the paper describe the steady-state 2D flow and heat transfer in terms of u(x,y), v(x,y), and θ(x,y). I have already set up the full PDE system, parameters, and boundary conditions (BCs) in Maple.

Now, iusing pdsolve(..., numeric, method=fd), 

Solve these equations for both square and H-shaped cavities using the given ICs and BCs, and

Generate Isotherm and Streamline plots (similar to Figs. 12 and 13 in the paper).

I have attached:

The PDF (showing equations and figures), and

My Maple worksheet containing the PDE definitions and parameters.

I would really appreciate guidance on:

Whether dsolve can be used effectively for this PDE system,

How to define the BCs correctly for the H-shaped cavity (especially the partially heated wall, θ=1 for 0.4 < y < 0.6), and

How to extract and plot the temperature (θ) and streamfunction (ψ) fields similar to the paper’s plots.

cavity_work_error.mw

I have more examples like this. Sometimes odetest give false negative result. dsolve solution is actually correct, but odetest does not return all zeros as result of its checking.

Here is an example.

interface(version);

`Standard Worksheet Interface, Maple 2025.1, Linux, June 12 2025 Build ID 1932578`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1881 and is the same as the version installed in this computer, created 2025, October 7, 16:4 hours Pacific Time.`

SupportTools:-Version();

`The Customer Support Updates version in the MapleCloud is 29 and is the same as the version installed in this computer, created June 23, 2025, 10:25 hours Eastern Time.`

ode:=x^2*diff(y(x),x)+sin(2*y(x)) = 1;
IC:=y(infinity)=11*Pi/4;
maple_sol:=dsolve([ode,IC]);
odetest(maple_sol,[ode,IC])

x^2*(diff(y(x), x))+sin(2*y(x)) = 1

y(infinity) = (11/4)*Pi

y(x) = -arctan((x+2)/(x-2))+3*Pi

[0, undefined]

#but the IC above should not be undefined. This belows shows it is correct.
limit(maple_sol,x=infinity);

limit(y(x), x = infinity) = (11/4)*Pi

#which is what the IC is.


Download odetest_problem_oct_8_2025.mw

Would you agree that odetest in the above should have returned [0,0] instead? Should this result be considered a bug?

Hello,

I have full access on .../.../version.txt but Maple tells me I have no write access...

Sorry for the previous post, thank you.

If I try with the install command I get the same error.

Kind regards to all

Jean-Michel

PS: have a look on the two inserted screenshots

Given an ode with IC. When solution is explicit, Maple resolves the constant of integration as expected and returns solution with no c__1 in it.

But when asked for implicit solution, also with same IC, it now returns solution with c__1 still there.

Is this by design or a bug? Should not constant of integration be resolved using IC in both cases? If unable to solve for c__1 because solution is implicit, should it then not return solution all?

Does this happen in earlier versions of Maple?

 

restart;

interface(version);

`Standard Worksheet Interface, Maple 2025.1, Linux, June 12 2025 Build ID 1932578`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1878 and is the same as the version installed in this computer, created 2025, September 28, 11:35 hours Pacific Time.`

SupportTools:-Version();

`The Customer Support Updates version in the MapleCloud is 29 and is the same as the version installed in this computer, created June 23, 2025, 10:25 hours Eastern Time.`

restart;

IC:=D(y)(0)=0;
ode:=diff(y(x),x)^2+x*y(x)=0:
sol:=dsolve([ode,IC]);

 

(D(y))(0) = 0

y(x) = 0, y(x) = -(1/9)*x^3

sol:=dsolve(ode,'implicit');

y(x) = 0, -x^2/((x^3+9*y(x))*(x^2+3*(-x*y(x))^(1/2)))+3*(-x*y(x))^(1/2)/((x^3+9*y(x))*(x^2+3*(-x*y(x))^(1/2)))-c__1 = 0, x^2/((x^3+9*y(x))*(-x^2+3*(-x*y(x))^(1/2)))+3*(-x*y(x))^(1/2)/((x^3+9*y(x))*(-x^2+3*(-x*y(x))^(1/2)))-c__1 = 0

#WHY did not resolve constant of integration here??
sol:=dsolve([ode,IC],'implicit');

x^2/((x^3+9*y(x))*(-x^2+3*(-x*y(x))^(1/2)))+3*(-x*y(x))^(1/2)/((x^3+9*y(x))*(-x^2+3*(-x*y(x))^(1/2)))-c__1 = 0, -x^2/((x^3+9*y(x))*(x^2+3*(-x*y(x))^(1/2)))+3*(-x*y(x))^(1/2)/((x^3+9*y(x))*(x^2+3*(-x*y(x))^(1/2)))-c__1 = 0, y(x) = 0

 


 

Download why_C_still_in_solution_maple_2025_1_oct_4_2025.mw

Hello, I have a Maple Flow worksheet that is formatted with a basic style template using headings and sections so that I can auto generate the table of contents. All of the numbered sections are in order, top-to-bottom in the worksheet. However, when Maple Flow auto generates the table of contents, it consistently gets the sections out of order - see a screenshot below - note Section 2 is at the end of the table of contents. The page numbers appear to be correct, but the physical placement of Section 2 is not. 

If anybody has encountered this problem in Maple Flow, I would appreciate some suggestions.

Thanks

For some reason, solve() works Ok, but PDEtools:-Solve causes kernel crash.

 

Attached worksheet.

Anyone knows why and can someone try to reproduce this? I am using Linux CaucyOS (arch linux based) and Maple 2025.1

 

interface(version);

`Standard Worksheet Interface, Maple 2025.1, Linux, June 12 2025 Build ID 1932578`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1878 and is the same as the version installed in this computer, created 2025, September 28, 11:35 hours Pacific Time.`

SupportTools:-Version();

`The Customer Support Updates version in the MapleCloud is 29 and is the same as the version installed in this computer, created June 23, 2025, 10:25 hours Eastern Time.`

restart;

eq:=[-3/2*_C6^2+4*(60588*_C6^3+6659802*_C6^2-7113718800*_C6+168667884119)/(40392*_C6-971364)-1/8*(-6*_C6+1)^2-4*(1406664*_C6^2-1186536946*_C6+27728821045)/(26928*_C6-647576)+5*_C6-125/6+9*(-1/24*(-6*_C6+16)^2-4*(1406664*_C6^2-1186536946*_C6+27728821045)/(26928*_C6-647576)+(60588*_C6^3+6659802*_C6^2-7113718800*_C6+168667884119)/(40392*_C6-971364))*(-49/2+_C6) = 4, -1/24*(-6*_C6+49)^2+191*(1406664*_C6^2-1186536946*_C6+27728821045)/(26928*_C6-647576)-(60588*_C6^3+6659802*_C6^2-7113718800*_C6+168667884119)/(40392*_C6-971364)+1/12*(-6*_C6+9801)^2 = 0];
Cs:={_C6};

[-(3/2)*_C6^2+4*(60588*_C6^3+6659802*_C6^2-7113718800*_C6+168667884119)/(40392*_C6-971364)-(1/8)*(-6*_C6+1)^2-4*(1406664*_C6^2-1186536946*_C6+27728821045)/(26928*_C6-647576)+5*_C6-125/6+9*(-(1/24)*(-6*_C6+16)^2-4*(1406664*_C6^2-1186536946*_C6+27728821045)/(26928*_C6-647576)+(60588*_C6^3+6659802*_C6^2-7113718800*_C6+168667884119)/(40392*_C6-971364))*(-49/2+_C6) = 4, -(1/24)*(-6*_C6+49)^2+191*(1406664*_C6^2-1186536946*_C6+27728821045)/(26928*_C6-647576)-(60588*_C6^3+6659802*_C6^2-7113718800*_C6+168667884119)/(40392*_C6-971364)+(1/12)*(-6*_C6+9801)^2 = 0]

{_C6}

solve(eq,Cs);

{_C6 = _C6}

PDEtools:-Solve(eq,Cs);


 

Download maple_crash_Solve_oct_3_2025.mw

Also reported to Maplesoft support.

 

I found very strange behaviour of Maple 2025.1 on Linux.

Same exact code.  Calling timelimit(sol,ode) twice on two different solutions. If I do not add 

         Physics:-Setup(assumingusesAssume = true)

At the start, then both timelimits finish OK. But once  Physics:-Setup(assumingusesAssume = true) is added at the start, the second timelimit hangs.

I waited 2 hrs and nothing happens. Maple just freezes. Can't even stop the server from worksheet by clicking on the red button at lower left corner. 

This is using latest Physics.  Does anyone know why this happens? It seems due to some memory cache issue?

Make sure to save all your work before trying this just in case you have to kill Maple application.

The strange thing, unable to stop the server by clicking on red button or clicking on RESTART KERNEL icon at top, or even clicking on the debuger icon at lower left corner. Only way was to kill Maple itself from Linux command line.

interface(version);

`Standard Worksheet Interface, Maple 2025.1, Linux, June 12 2025 Build ID 1932578`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1878 and is the same as the version installed in this computer, created 2025, September 28, 11:35 hours Pacific Time.`

SupportTools:-Version();

`The Customer Support Updates version in the MapleCloud is 29 and is the same as the version installed in this computer, created June 23, 2025, 10:25 hours Eastern Time.`

restart;

Example 1. Not using Physics:-Setup(assumingusesAssume = true): gives NO hang

 

sol_1:=y(x) = 1/2*(3*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*
sec(_Z)^2-8*3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^2
+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-\
8*3^(1/2))^(2/3))+12*_C2*3^(1/2)+12*3^(1/2)*x+36*I*_C2+36*I*x+6*_Z))^3*3^(1/2)+
9*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8*
3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*
sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^
(2/3))+12*_C2*3^(1/2)+12*3^(1/2)*x+36*I*_C2+36*I*x+6*_Z))^2+3*3^(1/2)*tan(
RootOf(2*3^(1/2)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(1/3)+2)-3^(1/2
)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(2/3)-2*(3*3^(1/2)*tan(_Z)*sec
(_Z)^2-8+9*sec(_Z)^2)^(1/3)+4)+36*I*_C2+36*I*x+12*_C2*3^(1/2)+12*3^(1/2)*x+6*_Z
))+1)^(1/3)*(I*3^(1/2)-1):
ode:=diff(y(x),x)-y(x)^3 = 8:
timelimit(30,odetest(sol_1,ode));

Error, (in simplify/ln/relations) time expired

 

sol_2:=y(x) = -1/2*(3*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)
*sec(_Z)^2-8*3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^
2+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2
-8*3^(1/2))^(2/3))+12*_C3*3^(1/2)+12*3^(1/2)*x-36*I*_C3-36*I*x+6*_Z))^3*3^(1/2)
+9*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8
*3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*
sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^
(2/3))+12*_C3*3^(1/2)+12*3^(1/2)*x-36*I*_C3-36*I*x+6*_Z))^2+3*3^(1/2)*tan(
RootOf(2*3^(1/2)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(1/3)+2)-3^(1/2
)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(2/3)-2*(3*3^(1/2)*tan(_Z)*sec
(_Z)^2-8+9*sec(_Z)^2)^(1/3)+4)-36*I*_C3-36*I*x+12*_C3*3^(1/2)+12*3^(1/2)*x+6*_Z
))+1)^(1/3)*(1+I*3^(1/2)):
timelimit(30,odetest(sol_2,ode));

Error, (in collect) time expired

 

Example 2. using Physics:-Setup(assumingusesAssume = true): second timelimit always hangs

 

restart;

Physics:-Setup(assumingusesAssume = true):

sol_1:=y(x) = 1/2*(3*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*
sec(_Z)^2-8*3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^2
+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-\
8*3^(1/2))^(2/3))+12*_C2*3^(1/2)+12*3^(1/2)*x+36*I*_C2+36*I*x+6*_Z))^3*3^(1/2)+
9*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8*
3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*
sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^
(2/3))+12*_C2*3^(1/2)+12*3^(1/2)*x+36*I*_C2+36*I*x+6*_Z))^2+3*3^(1/2)*tan(
RootOf(2*3^(1/2)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(1/3)+2)-3^(1/2
)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(2/3)-2*(3*3^(1/2)*tan(_Z)*sec
(_Z)^2-8+9*sec(_Z)^2)^(1/3)+4)+36*I*_C2+36*I*x+12*_C2*3^(1/2)+12*3^(1/2)*x+6*_Z
))+1)^(1/3)*(I*3^(1/2)-1):
ode:=diff(y(x),x)-y(x)^3 = 8:
timelimit(30,odetest(sol_1,ode));

Error, (in expand) time expired

 

#this below will now hang

sol_2:=y(x) = -1/2*(3*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)
*sec(_Z)^2-8*3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^
2+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2
-8*3^(1/2))^(2/3))+12*_C3*3^(1/2)+12*3^(1/2)*x-36*I*_C3-36*I*x+6*_Z))^3*3^(1/2)
+9*tan(RootOf(2*3^(1/2)*ln(2*3^(1/6)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8
*3^(1/2))^(1/3))-3^(1/2)*ln(4*3^(1/3)-2*3^(1/6)*(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*
sec(_Z)^2-8*3^(1/2))^(1/3)+(9*tan(_Z)*sec(_Z)^2+9*3^(1/2)*sec(_Z)^2-8*3^(1/2))^
(2/3))+12*_C3*3^(1/2)+12*3^(1/2)*x-36*I*_C3-36*I*x+6*_Z))^2+3*3^(1/2)*tan(
RootOf(2*3^(1/2)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(1/3)+2)-3^(1/2
)*ln((3*3^(1/2)*tan(_Z)*sec(_Z)^2-8+9*sec(_Z)^2)^(2/3)-2*(3*3^(1/2)*tan(_Z)*sec
(_Z)^2-8+9*sec(_Z)^2)^(1/3)+4)-36*I*_C3-36*I*x+12*_C3*3^(1/2)+12*3^(1/2)*x+6*_Z
))+1)^(1/3)*(1+I*3^(1/2)):
timelimit(30,odetest(sol_2,ode));


Download hangs_timelimit_with_physics_maple_2025_1_oct_2_2025.mw

Could someone try to reproduce this on their Maple? If so, I will send bug report.

Never seen such a message before

Here is MWE, Trace shows it comes from (SolveTools:-PolynomialSystemSolvers:-PseudoResultant:-AttemptFactorization,2)

 

restart;

interface(version);

`Standard Worksheet Interface, Maple 2025.1, Linux, June 12 2025 Build ID 1932578`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1878 and is the same as the version installed in this computer, created 2025, September 28, 11:35 hours Pacific Time.`

SupportTools:-Version();

`The Customer Support Updates version in the MapleCloud is 29 and is the same as the version installed in this computer, created June 23, 2025, 10:25 hours Eastern Time.`

ode:=diff(y(x),x$2)+3*y(x)+D(y)(3)=0;
IC:=y(1)+4*y(2)+y(4)=0;

diff(diff(y(x), x), x)+3*y(x)+(D(y))(3) = 0

y(1)+4*y(2)+y(4) = 0

dsolve(ode)

x+(1/3)*3^(1/2)*(tan(3^(1/2)*x)-arctan(tan(3^(1/2)*x)))-((1/3)*(D(y(x)))(3)*(1+tan(3^(1/2)*x)^2)^(1/2)+(1+tan(3^(1/2)*x)^2)^(1/2)*y(x))*c__1-c__2 = 0

dsolve([ode,IC])

Error, (in dsolve) this is a bug

tracelast

 dsolve called with arguments: [diff(diff(y(x), x), x)+3*y(x)+(D(y))(3) = 0, y(1)+4*y(2)+y(4) = 0], arbitraryconstants = subscripted, atomizenames = true, build = false, numeric = false, type = none
 #(dsolve,80): error

 \`dsolve/IC\` called with arguments: [diff(diff(y(x), x), x)+3*y(x)+(D(y))(3) = 0, y(1)+4*y(2)+y(4) = 0], {y(x)}, skipimplicit = false, skippparticularsolforlinearODEs = true, solution = {}, usesolutions = particular and general
 #(\`dsolve/IC\`,53): return procname(_passed,':-usesolutions' =  "general and particular")

 \`dsolve/IC\` called with arguments: [diff(diff(y(x), x), x)+3*y(x)+(D(y))(3) = 0, y(1)+4*y(2)+y(4) = 0], {y(x)}, skipimplicit = false, skippparticularsolforlinearODEs = true, solution = {}, usesolutions = general and particular
 #(\`dsolve/IC\`,57): ans := procname(_passed,':-usesolutions = "general"');

 \`dsolve/IC\` called with arguments: [diff(diff(y(x), x), x)+3*y(x)+(D(y))(3) = 0, y(1)+4*y(2)+y(4) = 0], {y(x)}, skipimplicit = false, skippparticularsolforlinearODEs = true, solution = {}, usesolutions = general
 #(\`dsolve/IC\`,277): zz := map(op,{\`dsolve/IC/_C\`({ANS[i]},funcs,x,ics)});

 \`dsolve/IC/_C\` called with arguments: {y(x) = -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(3^(1/2)*x)^2)^(1/2)-3^(1/2)*tan(3^(1/2)*x)+3^(1/2)*arctan(tan(3^(1/2)*x))+3*_C[2]-3*x)/((1+tan(3^(1/2)*x)^2)^(1/2)*_C[1])}, {y(x)}, x, [y(1) = _C1, y(2) = _C2, y(4) = -_C1-4*_C2]
 #(\`dsolve/IC/_C\`,1): ans := \`dsolve/IC/_C/do\`(solns,depvars,t,inits,'evaluated_ans', "default",':-giveup = giveup');

 \`dsolve/IC/_C/do\` called with arguments: {y(x) = -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(3^(1/2)*x)^2)^(1/2)-3^(1/2)*tan(3^(1/2)*x)+3^(1/2)*arctan(tan(3^(1/2)*x))+3*_C[2]-3*x)/((1+tan(3^(1/2)*x)^2)^(1/2)*_C[1])}, {y(x)}, x, [y(1) = _C1, y(2) = _C2, y(4) = -_C1-4*_C2], evaluated_ans, default, giveup = giveup, usecansolve = false
 #(\`dsolve/IC/_C/do\`,103): csol := [\`ODEtools/Solve/EnvDropMultiplicity\`(eqns,consts)];

 \`ODEtools/Solve/EnvDropMultiplicity\` called with arguments: {-(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(3^(1/2))^2)^(1/2)-3^(1/2)*tan(3^(1/2))+3^(1/2)*(3^(1/2)-Pi)+3*_C[2]-3)/((1+tan(3^(1/2))^2)^(1/2)*_C[1]) = _C1, -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(2*3^(1/2))^2)^(1/2)-3^(1/2)*tan(2*3^(1/2))+3^(1/2)*(2*3^(1/2)-Pi)+3*_C[2]-6)/((1+tan(2*3^(1/2))^2)^(1/2)*_C[1]) = _C2, -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(4*3^(1/2))^2)^(1/2)-3^(1/2)*tan(4*3^(1/2))+3^(1/2)*(4*3^(1/2)-2*Pi)+3*_C[2]-12)/((1+tan(4*3^(1/2))^2)^(1/2)*_C[1]) = -_C1-4*_C2}, {_C1, _C2, _C[1], _C[2]}, keepalreadysolveduntouched = false, removelabel = false
 #(\`ODEtools/Solve/EnvDropMultiplicity\`,29): sol := :-solve(ee,X,_rest)

 solve called with arguments: {-(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(3^(1/2))^2)^(1/2)-3^(1/2)*tan(3^(1/2))+3^(1/2)*(3^(1/2)-Pi)+3*_C[2]-3)/((1+tan(3^(1/2))^2)^(1/2)*_C[1]) = _C1, -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(2*3^(1/2))^2)^(1/2)-3^(1/2)*tan(2*3^(1/2))+3^(1/2)*(2*3^(1/2)-Pi)+3*_C[2]-6)/((1+tan(2*3^(1/2))^2)^(1/2)*_C[1]) = _C2, -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(4*3^(1/2))^2)^(1/2)-3^(1/2)*tan(4*3^(1/2))+3^(1/2)*(4*3^(1/2)-2*Pi)+3*_C[2]-12)/((1+tan(4*3^(1/2))^2)^(1/2)*_C[1]) = -_C1-4*_C2}, {_C1, _C2, _C[1], _C[2]}, AllSolutions = FAIL, ConditionalSolutions = FAIL, DropMultiplicity = FAIL, Explicit = FAIL, MaxSols = FAIL, SolveOverReals = FAIL, SymbolicSolutions = true, TryHard = FAIL, UseAssumptions = false, domain = default, parameters = {}, parametric = false, split = false, useunits = FAIL
 #(solve,133): _MaxSols := oldmaxsols

 Engine:-Main called with arguments: {-(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(3^(1/2))^2)^(1/2)-3^(1/2)*tan(3^(1/2))+3^(1/2)*(3^(1/2)-Pi)+3*_C[2]-3)/((1+tan(3^(1/2))^2)^(1/2)*_C[1]) = _C1, -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(2*3^(1/2))^2)^(1/2)-3^(1/2)*tan(2*3^(1/2))+3^(1/2)*(2*3^(1/2)-Pi)+3*_C[2]-6)/((1+tan(2*3^(1/2))^2)^(1/2)*_C[1]) = _C2, -(1/3)*(_C[1]*(D(_Z))(3)*(1+tan(4*3^(1/2))^2)^(1/2)-3^(1/2)*tan(4*3^(1/2))+3^(1/2)*(4*3^(1/2)-2*Pi)+3*_C[2]-12)/((1+tan(4*3^(1/2))^2)^(1/2)*_C[1]) = -_C1-4*_C2}, {}, {_C1, _C2, _C[1], _C[2]}
 #(SolveTools:-Engine:-Main,37): sol := [SolveTools:-PolynomialSystem(eqns,vars,ineqs,':- maxsols' = \`if\`(type([_MaxSols],[{integer, infinity}]) and 0 < _MaxSols,_MaxSols,100))]

 PolynomialSystem:-ModuleApply called with arguments: {-(1/3)*(_X000003*(D(_Z))(3)*(1+tan(3^(1/2))^2)^(1/2)-3^(1/2)*tan(3^(1/2))+3^(1/2)*(3^(1/2)-Pi)+3*_X000004-3)/((1+tan(3^(1/2))^2)^(1/2)*_X000003) = _X000001, -(1/3)*(_X000003*(D(_Z))(3)*(1+tan(2*3^(1/2))^2)^(1/2)-3^(1/2)*tan(2*3^(1/2))+3^(1/2)*(2*3^(1/2)-Pi)+3*_X000004-6)/((1+tan(2*3^(1/2))^2)^(1/2)*_X000003) = _X000002, -(1/3)*(_X000003*(D(_Z))(3)*(1+tan(4*3^(1/2))^2)^(1/2)-3^(1/2)*tan(4*3^(1/2))+3^(1/2)*(4*3^(1/2)-2*Pi)+3*_X000004-12)/((1+tan(4*3^(1/2))^2)^(1/2)*_X000003) = -_X000001-4*_X000002}, {_X000001, _X000002, _X000003, _X000004}, {}, FAIL, backsubstitute = true, domain = absolute, engine = default, explicit = false, maxsols = 100, preprocess = true, preservelabels = false, tryhard = true
 #(SolveTools:-PolynomialSystem:-ModuleApply,15): sol := SolveTools:-PolynomialSystem:-Main(SolveTools:-Utilities:-New( equations,notz,SolveTools:-Utilities:-Intersect(vars,indets(equations ))),':-backsub' = reallybacksub,':-domain' = domain,':-maxsols' =  realmaxsols,':-engine' = engine,':-preprocess' = preprocess,':- tryhard' = tryhard);

 PolynomialSystem:-Main called with arguments: [{-(1/3)*(_X000003*(D(_Z))(3)*(1+tan(3^(1/2))^2)^(1/2)-3^(1/2)*tan(3^(1/2))+3^(1/2)*(3^(1/2)-Pi)+3*_X000004-3)/((1+tan(3^(1/2))^2)^(1/2)*_X000003)-_X000001, -(1/3)*(_X000003*(D(_Z))(3)*(1+tan(2*3^(1/2))^2)^(1/2)-3^(1/2)*tan(2*3^(1/2))+3^(1/2)*(2*3^(1/2)-Pi)+3*_X000004-6)/((1+tan(2*3^(1/2))^2)^(1/2)*_X000003)-_X000002, -(1/3)*(_X000003*(D(_Z))(3)*(1+tan(4*3^(1/2))^2)^(1/2)-3^(1/2)*tan(4*3^(1/2))+3^(1/2)*(4*3^(1/2)-2*Pi)+3*_X000004-12)/((1+tan(4*3^(1/2))^2)^(1/2)*_X000003)+_X000001+4*_X000002}, {3*(1+tan(3^(1/2))^2)^(1/2)*_X000003 <> 0, 3*(1+tan(2*3^(1/2))^2)^(1/2)*_X000003 <> 0, 3*(1+tan(4*3^(1/2))^2)^(1/2)*_X000003 <> 0}, {_X000001, _X000002, _X000003, _X000004}, {}, true, false, 1, {_X000001, _X000002, _X000003, _X000004}], backsub = true, domain = absolute, engine = default, maxsols = 100, preprocess = true, tryhard = true
 #(SolveTools:-PolynomialSystem:-Main,86): sol := [SolveTools:-PolynomialSystemSolvers:- PseudoResultant(SolveTools:-Utilities:- GetEquations(sys),SolveTools:-Utilities:- GetVariables(sys),SolveTools:-Utilities:- GetInequations(sys),':-maxsols' = maxsols,':- tryhard' = tryhard)];

 PseudoResultant:-ModuleApply called with arguments: {(_X000003*(D(_Z))(3)*(-2*cos(3^(1/2))+1+sec(3^(1/2)))+3*_X000001*_X000003*(-2*cos(3^(1/2))+sec(3^(1/2)))+3*_X000002*_X000003+3^(1/2)*tan(3^(1/2)))/cos(2*3^(1/2)), -(sec(4*3^(1/2))+sec(3^(1/2)))*_X000003*(D(_Z))(3)+3*(sec(4*3^(1/2))-sec(3^(1/2)))*_X000001*_X000003+12*_X000002*sec(4*3^(1/2))*_X000003+3^(1/2)*Pi+3^(1/2)*tan(4*3^(1/2))-3^(1/2)*tan(3^(1/2))}, {_X000001, _X000002, _X000003}, {_X000003 <> 0}, backsub = true, maxsols = 100, tryhard = true
 #(SolveTools:-PolynomialSystemSolvers:-PseudoResultant:-ModuleApply,25): SolveTools:-PolynomialSystemSolvers:-PseudoResultant:-ApplySubstitution ({},[],numer(tm1),notzero union map(xx -> denom(xx) <> 0,tm1), unknowns);

 ApplySubstitution called with arguments: {}, [], {_X000003*(D(_Z))(3)*sec(3^(1/2))+3*_X000001*sec(3^(1/2))*_X000003-2*_X000003*(D(_Z))(3)*cos(3^(1/2))-6*_X000001*_X000003*cos(3^(1/2))+3^(1/2)*tan(3^(1/2))+_X000003*(D(_Z))(3)+3*_X000002*_X000003, -_X000003*(D(_Z))(3)*sec(4*3^(1/2))+3*_X000001*sec(4*3^(1/2))*_X000003+12*_X000002*sec(4*3^(1/2))*_X000003+3^(1/2)*Pi+3^(1/2)*tan(4*3^(1/2))-_X000003*(D(_Z))(3)*sec(3^(1/2))-3*_X000001*sec(3^(1/2))*_X000003-3^(1/2)*tan(3^(1/2))}, {1 <> 0, _X000003 <> 0, cos(2*3^(1/2)) <> 0}, {_X000001, _X000002, _X000003}
 #(SolveTools:-PolynomialSystemSolvers:-PseudoResultant:-ApplySubstitution,48): eqns := map(SolveTools:-PolynomialSystemSolvers:-PseudoResultant:- AttemptFactorization,eqns,not0,unknowns);

 AttemptFactorization called with arguments: _X000003*(D(_Z))(3)*sec(3^(1/2))+3*_X000001*sec(3^(1/2))*_X000003-2*_X000003*(D(_Z))(3)*cos(3^(1/2))-6*_X000001*_X000003*cos(3^(1/2))+3^(1/2)*tan(3^(1/2))+_X000003*(D(_Z))(3)+3*_X000002*_X000003, {_X000003 <> 0, cos(2*3^(1/2)) <> 0}, {_X000001, _X000002, _X000003}
 #(SolveTools:-PolynomialSystemSolvers:-PseudoResultant:-AttemptFactorization,2): error \`this is a bug\`

Error, (in dsolve) this is a bug

 locals defined as: e = e

 


 

Download dsolve_error_this_is_bug_2025_1_oct_2_2025.mw

Note that changing the IC to IC:=y(1)+4*y(2)=0; makes it work with no error.

It is only when adding y(4) does the error shows up.

update Bug report emailed to Maplesoft.

 

 

Hi! how I install Maple 2025 and Mathematica in my laptop?
Provide me Complete Set-up.

I feel that it is increasingly common for answers to generate no reaction from their authors.

Perhaps the author simply voted up... but in that case, would it be possible to indicate this (something like "XXX voted up")? 

This would avoid wasting time responding to the same author in the future, as it doesn't seem to care about commenting the answer.

Hi there.

There is an issue with following limits in Maple 2025:

Maple returned an incorrect zero answers. Plotting functions we see that non-zero limits do exist:

Thank you.

limits.mw

I would like to keep writing commands on the same line without automatically creating a new line break. Is there a way to achieve this in Maple?

I want to change the datatype of a column of a Dataframe imported from Excel.

The import succeeds, and I can change the data type of numeric columns (from the default 'anything' to, say, float).

But conversion fails for all string columns. For example:

DataNew := SubsDatatype(Data, "UN Region", string);

throws the following error:

Error, (in DataSeries:-SubsDatatype) in datatype conversion; try using the 'conversion' option for data type string

The column in question has values such as "Southern Asia", which I would have thought would convert.

What am I doing wrong?

Did you intend on doing the diffetentiation elememtwise, ie. on each of the Matrix entriez?

Did you try,

   diff~(V, x)

or,

  map(diff, V, x)

?

I want to convert an XYZ file into a hydrogen-depleted heavy-atom molecule in Maple. Since XYZ has only coordinates, I’ll infer bonds by comparing inter-atomic distances to the sum of covalent radii ± tolerance, then remove hydrogens and output a heavy-atom molecule with only these bonds. What tolerances are sensible, and is there any built-in way in Maple to do this? Kind help with a maple code to do this.

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