Items tagged with system system Tagged Items Feed


I have been using MapleSoft since 2013 to solve mathematical problem. However, I could not solve the following set of differential equations.  Would you please, solve the problem and return the file how you solve it? Thanks in advance.


i need help to translate a system which is given below to a for loop.

Other wise i am writing it with myself. 

instead of doing it like that 


sys := [galerkin_funcs[1], galerkin_funcs[2], galerkin_funcs[3], galerkin_funcs[4], galerkin_funcs[5], galerkin_funcs[6], galerkin_funcs[7], galerkin_funcs[8], galerkin_funcs[9], galerkin_funcs[10]];

var := [w[1], w[2], w[3], w[4], w[5], w[6]];

Kmat, Fmat := GenerateMatrix(sys, var);

i want to do it like that.


for i to N+4 do

sys(1,i) := galerkin_funcs[i] 

end do

for i to N do

var(1,i) := w[i] 

end do

After that i will generate matrix with this comman Kmat, Fmat := GenerateMatrix(sys, var);

But this for loop i wrote is not doing the i want to do.

Thanks for your help.



a system of monomials, which has 5 equations for 5 variables , have more than one solutions,

first solution is my wanted solution,

how to eliminate other unwanted solutions?


1. add more equations to eliminate unwanted solutions? how to do?


2. edit existing system to eliminate unwanted solutions? how to do?

    a.  add extra terms to some equations?


what is the cause that make it having more than one solutions?

can this reason help to edit existing system?


i succeed with adding extra equation,a1+a2+a3+a4+a5-(6+s) =0  in 3 variables case, it calculate very fast within 1 second.

but when calculating 5 variables, it evaluating a very very long time, what is the problem


without extra equation a1+a2+a3+a4+a5+a6+a7-(1+2+3+4+5+s), it get result within 1 second, but after adding this extra equation, it is like dead loop,

my surface computer run with large fans noise and very hot.

Question regarding solving the equation systems. 

See maple file for equations.

Are there any examples of network solutions such as mine systems in Maple.
I wrote in the Maple system of partial differential equations describing the process of filtration combustion.
I'm a novice. I do not quite understand how to solve it.
Online a lot of "simple" examples. I need something very similar to my case.

Hello all

I am trying to write  a tutorial about systems of linear equations, and I want to demonstrate the idea that when you have a system of 3 euqtions with 3 unknowns, the solution is the intersection point between these planes. Plotting 3 planes in Maple 2015 is fairly easy (you plot one and just drag the others in), but I don't know how to plot the intersection point. Can you help please ?


My equations are:




The intersection point is (29,16,3)


Thank you !

I have a vector of dimension n with each component being an equation of a linear system.

Can maple convert this Vector to a Matrix-Vector form with the matrix being constant coefficients?

There is a desire to explore the process of filtration combustion. To do this, you must solve a system of differential equations in partial derivatives.
I write down all the equations.
Boundary conditions in Maple 2015.0 interpreted incorrectly.
I need to write like that:



given that:

It turns out so:



ie somewhere lost derivatives




As in Maple record boundary conditions correct?

Thanking you in advance.

I am attempting to solve a system of second order ODEs. I place conditions on the solutions and use the solve command to figure the correct constants for the general solutions of the ODEs; however, the conditions do not appear to hold after I substitute the constants back into the general solutions. Any help would be greatly appreciated. Here's the code and an explanation:

First some constants

> A := 1; B := 9/10;
> j := 1-1/B;

 This is our homogeneous odes. I will give the general solutions of the inhomogeneous system momentarily 

> eqnv1 := diff(v1(x), `$`(x, 2)) = (1-1/(j+1))*v1(x)+v2(x)/(j+1);
> eqnv2 := diff(v2(x), `$`(x, 2)) = -v1(x)/(A*(j+1))+(B/A+1/(A*(j+1)))*v2(x);

Next we get the general solution of this sytem of odes.

> soln := dsolve([eqnv1, eqnv2])

Next we have our solutions of the inhomogeneous problem1. Basically solution v1neg, v2neg on [0,xi] and v1pos, v2pos on [xi,1]. We will assume v1,v2 are C^1 across xi; however, the location of xi is not known at this time so they must remain split.

> v1neg := op([1, 2], soln)-1;
> v2neg := op([2, 2], soln)-1/B;
> v1pos := op([1, 2], soln)+1;
> v2pos := op([2, 2], soln)+1/B;

There's probably a better way to do this, but I relabeled the constants:

> v1negc := subs([_C1 = a[1], _C2 = a[2], _C3 = a[3], _C4 = a[4]], v1neg);
> v2negc := subs([_C1 = a[1], _C2 = a[2], _C3 = a[3], _C4 = a[4]], v2neg);
> v1posc := subs([_C1 = a[5], _C2 = a[6], _C3 = a[7], _C4 = a[8]], v1pos);
> v2posc := subs([_C1 = a[5], _C2 = a[6], _C3 = a[7], _C4 = a[8]], v2pos);

Next we have eight conditions the solutions must satisfy. Namely v1, v2 are C^1 across xi and v1',v2' are 0 at {0,1}.

> syscon1 := subs(x = xi, v1negc) = subs(x = xi, v1posc);
> syscon2 := subs(x = xi, v2negc) = subs(x = xi, v2posc);
> syscon3 := subs(x = xi, diff(v1negc, x)) = subs(x = xi, diff(v1posc, x));
> syscon4 := subs(x = xi, diff(v2negc, x)) = subs(x = xi, diff(v2posc, x));
> syscon5 := subs(x = 0, diff(v1negc, x)) = 0;
> syscon6 := subs(x = 0, diff(v2negc, x)) = 0;
> syscon7 := subs(x = 1, diff(v1posc, x)) = 0;
> syscon8 := subs(x = 1, diff(v2posc, x)) = 0;

We solve to get the constants for the solutions.

> constants := simplify(evalf(solve({syscon1, syscon2, syscon3, syscon4, syscon5, syscon6, syscon7, syscon8}, {a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8]})));

We substitute the values for the constants.

> a[1] := op([1, 2], constants); a[2] := op([2, 2], constants); a[3] := op([3, 2], constants); a[4] := op([4, 2], constants); a[5] := op([5, 2], constants); a[6] := op([6, 2], constants); a[7] := op([7, 2], constants); a[8] := op([8, 2], constants);

Lastly we try to verify that the conditions from earlier hold:

> evalf(subs(xi = .2, subs(x = xi, v1negc-v1posc)));
> evalf(subs(xi = .2, subs(x = xi, v2negc-v2posc)));
> evalf(subs([x = 0, xi = .2], diff(v1negc, x)));

They should hold for any xi, but they don't appear to. All of these should be 0. For a large xi, the numbers get very large so I was thinking perhaps roundoff error, but even when I do an exact solution and then evalf just at the end, I still have large error so I'm not sure what the problem is. Sorry for the long question. Thanks so much for the help.


Anyone could help me in solving the following system of equations to get constants C1, C2, C3 and C4. MALPE give me this "soution may have been lost".  The MAPLE sheet is also attached.



Eq1:=simplify(C3*exp(-(1/4)*(C2*(x^2-2*0)+sqrt(C2*(x^2-2*0)^2+4*M*(x^2-2*0)*w1*(x^2-2*0)))/w1)+C4*exp((1/4)*(-C2*(x^2-2*0)+sqrt(C2*(x^2-2*0)^2+4*M*(x^2-2*0)*w1*(x^2-2*0)))/w1)-U) = 0;

C3*exp(-(1/4)*(C2*x^2+(x^4*(4*M*w1+C2))^(1/2))/w1)+C4*exp(-(1/4)*(C2*x^2-(x^4*(4*M*w1+C2))^(1/2))/w1)-U = 0


Eq2:=simplify(exp(-(1/4)*(C2+sqrt(C2^2+4*M*w1))*(x^2-2*0)/w1)*C3*x+exp((1/4)*(-C2+sqrt(C2^2+4*M*w1))*(x^2-2*0)/w1)*C4*x+C2-V-z) = 0;

exp(-(1/4)*(C2+(C2^2+4*M*w1)^(1/2))*x^2/w1)*C3*x+exp(-(1/4)*(C2-(C2^2+4*M*w1)^(1/2))*x^2/w1)*C4*x+C2-V-z = 0


Eq3:=simplify((-2*w2*w5*ln(C3*exp(-(1/2)*sqrt(w2*w4*(w2*w4+w3*w6))*C2*(x^2-2*0)/(w2*w4*w5))-C4)*sqrt(w2*w4*(w2*w4+w3*w6))+w2*w5*(-w2*w4+sqrt(w2*w4*(w2*w4+w3*w6)))*ln(exp(-(1/2)*sqrt(w2*w4*(w2*w4+w3*w6))*C2*(x^2-2*0)/(w2*w4*w5)))+C1*w3*w6*sqrt(w2*w4*(w2*w4+w3*w6)))/(sqrt(w2*w4*(w2*w4+w3*w6))*w3*w6)-1)= 0;

(-ln(exp(-(1/2)*(w2*w4*(w2*w4+w3*w6))^(1/2)*C2*x^2/(w2*w4*w5)))*w2^2*w4*w5+C1*w3*w6*(w2*w4*(w2*w4+w3*w6))^(1/2)-2*w2*w5*ln(C3*exp(-(1/2)*(w2*w4*(w2*w4+w3*w6))^(1/2)*C2*x^2/(w2*w4*w5))-C4)*(w2*w4*(w2*w4+w3*w6))^(1/2)+ln(exp(-(1/2)*(w2*w4*(w2*w4+w3*w6))^(1/2)*C2*x^2/(w2*w4*w5)))*(w2*w4*(w2*w4+w3*w6))^(1/2)*w2*w5-(w2*w4*(w2*w4+w3*w6))^(1/2)*w3*w6)/((w2*w4*(w2*w4+w3*w6))^(1/2)*w3*w6) = 0


Eq4:= simplify((-C2*x^2*w2*w4-.50*C2*x^2*w3*w6+sqrt(w2*w4*(w2*w4+w3*w6))*C2*x^2+2.*w2*w4*w5*ln(w3^4*w6^2*(C3^2*exp(-1.0*sqrt(w2*w4*(w2*w4+w3*w6))*C2*x^2/(w2*w4*w5))-2*C3*exp(-.5*sqrt(w2^2*w4^2+w2*w3*w4*w6)*C2*x^2/(w2*w4*w5))*C4+C4^2)/(w2*w4*(w2*w4+w3*w6)*C2^2))-5.544000000*w2*w4*w5-w3^2*w6)/(w3^2*w6)) = 0;

(-C2*x^2*w2*w4-.5000000000*C2*x^2*w3*w6+(w2*w4*(w2*w4+w3*w6))^(1/2)*C2*x^2+2.*w2*w4*w5*ln(w3^4*w6^2*(C3^2*exp(-(w2*w4*(w2*w4+w3*w6))^(1/2)*C2*x^2/(w2*w4*w5))-2.*C3*exp(-.5*(w2*w4*(w2*w4+w3*w6))^(1/2)*C2*x^2/(w2*w4*w5))*C4+C4^2)/(w2*w4*(w2*w4+w3*w6)*C2^2))-5.544000000*w2*w4*w5-w3^2*w6)/(w3^2*w6) = 0


solve({Eq1, Eq2, Eq3,Eq4}, {C1, C2, C3,C4});

Warning, solutions may have been lost







hi.may  help me for solve this nonlinear equations by numeric solver maple39.d39.pdfocx39.pdf

thanks alot

file format is pdf and word type


and show whether there is sink or source?

ode1:=a(t)*(diff(a(t), t))+c(t)*(diff(c(t), t))=3*t;
ode2:=a(t)*(diff(a(t), t))+a(t)*(diff(a(t), t))*b(t)*(diff(b(t), t))*c(t)*(diff(c(t), t))=3*t;
ode3:=a(t)*(diff(a(t), t))+a(t)*(diff(a(t), t))*c(t)*(diff(c(t), t))+a(t)*(diff(a(t), t))*b(t)*(diff(b(t), t))*c(t)*(diff(c(t), t))=2*t;

DEtools[DEplot3d]({ode1,ode2,ode3},[a(t),b(t),c(t)],t=0.5..1.4,a=0..1.4,b=0..1.4,c=0..1.4,[[a(1)=1,b(1)=2,c(1)=3]],scene=[a(t),b(t),c(t)], arrows=medium);


unable to convert to explicit first order system, do not understand this error message

Hi dear friends 

Is there an interactive package management utility or a way for solving following problem?

for m>=4 It dosent work!

Digits :=30: m := 3: g :=0.3: nu := 0.2: a := 1:
w := sum(b[n]*cos(n*r), n = 1 .. m):
W := simplify( subs( solve( { subs(r = 1, diff(w, r$2)+nu*diff(w,r))},{ b[1] }),w)):
F:= int( ((d2+d1/r)^2-(2*(1-nu))*d2*d1/r)*r*(1+g*r/a)^3,r = 0 .. a) /int( d1^2*r,r = 0 .. a):
FW := simplify( subs(solve( {seq(subs(r=n/m,diff(F,b[n])),n=2..m)},{ seq(b[j], j = 2 .. m) }),F));

Hello All,

I have the PDE system shown below. It is a simple system for 2 unknown functions f1(x,t) and f2(x,t). Also, say we have x=x(t)=e^t for example. How does one solve such PDE system with Maple? I tried including the condition x=e^t in the PDE system itself, but got "System inconsistent" error message. x=x(t) can be looked at as an additional constraint and I am baffled how do I feed it into the PDE solver. 


Perhaps someone has experience with such systems?




I'm having a problem with my student work, about to have a solution of 6 equations... Can help me in this file? i dont know how to solve this... this had-me a null solve...



Thanks for the help =)


M1 := 0.15e5;





















`σadm` := 175*10^6;







Atria := (3.5*12)/(LBC+LCD)



Ctria := LAB+LBC+(1/3)*(2*(LCD+LDE))



AiXil := Atria*Ctria



C := AiXil/Atria






SumFX := FAx;



SumFY := FAy+FCy+FEy-F5-QTria;



SumMA := FCy*(LAB+LBC)-F5*(LAB+LBC)+FEy*(LAB+LBC+LCD+LDE)+M1-MA-QTria*Ctria;






EIYac := EIYo+`EIθo`*x+M1*(x+0)^3/factorial(3);



EIYce := EIYac+FCy*(x-4)^3/factorial(3)-F5*(x-4)^3/factorial(3)-q5*(x-4)^5/((3.5)*factorial(5));



EIYef := EIYce+FEy*(x-7.5)^3/factorial(3)+(1/3)*q5*(x-7.5)^5/factorial(5);



`EIθac` := diff(EIYac, x);



`EIθce` := diff(EIYce, x);



`EIθef` := diff(EIYef, x);




Mac := diff(`EIθac`, x);



Mce := diff(`EIθce`, x);



Mef := diff(`EIθef`, x);




Vac := diff(Mac, x);



Vce := diff(Mce, x);



Vef := diff(Mef, x);




x := 0:

`EIθo` = 0


EIYo = 0


x := 4:



x := 7.5:



SOL := solve({CF1, CF2, CF3, CF4, SumFY, SumMA}, {EIyo, FAy, FCy, FEy, MA, `EIyθo`});








1 2 3 4 5 6 7 Last Page 1 of 16