Items tagged with equation equation Tagged Items Feed

I am trying to solve an equation by continuation method (one vairable and one parameter) containing more than 1000 terms and also hight exponents like 800. I want to get omega' values for different 'p' values.The maple file  is appended below. the link is

Many thanks in advance.

Hi,   I want to substitute every  U[jj+1,-1] by U[jj+1,1] in these lines. Many thanks to send your remarks.

for jj from 1 to M do:
  sys[jj] := eval(BTCS_general,j=jj);

subs(U[jj,M+2]=U[jj,M]; U[jj+1,-1]=U[jj+1,1], sys);

  Why in this equation U[jj+1,-1] doesnt changed by U[jj+1,1];
                    s u[i + 1, -1]   4 s u[i + 1, 0]   6 s u[i + 1, 1]
      u[i + 1, 1] + -------------- - --------------- + ---------------
                           4                4                 4       
                          h                h                 h        

           4 s u[i + 1, 2]   s u[i + 1, 3]          
         - --------------- + ------------- = u[i, 1]
                  4                4                
                 h                h                 

Hi ;

I need your help to write the system contains all these equation:

# system 1
# system 2
for j from 1 to N do
u[0, j] := (1/4)*(u[1,j]+u[1,j]+u[0, j-1]+u[0,j+1]-f[0,j]*h^2);
end do;
# System 3
for j from 1 to N do
u[N+1, j] := (1/4)*(u[N, j]+u[N-1,j]+u[N+1, j-1]+u[N+1, j+1]-f[N+1,j]*h^2);
end do;
 eqs := [ seq(seq(Stencil[1](h,i,j,u,f),i=1..N),j=1..N)];

How can collect these system 1 system2, system3 ans system4 in a set with one name.

sys:=[eqs,system3,system2,system2]; ( sys: here contains all the equation).

Thanks you.



Please I need help in this subject. I would like to compare the numerical solution obtained by finite difference and pdsolve/numeric.

The equation considred is  diffusion Equation using Forward-time centered-space (FTCS) stencil
The code work well with Dirichlet boundary condition, but I want to let  x=-1  Dirichlet boundary condition but on x=1, we put a Neumann condition likeeval( diff(u(t,x),x),x=1)=1. Thank you very much to put the necessary in the attached code the changment.      
Many thinks.    

Hi Maple-Prime-ers!

I have a system of equations, containing 18 variables and 13 equations, making this a 5 degree of freedom (DOF) system.  I would like to analytically solve each of the equations in terms of each of these DOFs.  Normally I would use solve(system, dof_variables) to accomplish this, but it doesn't return anything.  Not even [].

I can solve this system by hand.  I've included a hand-solution involving isolate() and subs() in the attached worksheet.  I'm looking to incorporate this in an optimization algorithm with varying system, so I would like an automated way of doing this.

Does anybody have any suggestions to get solve to work as intended?


Here is the system I am talking about:



The free variables are:  {FD_T, FD_W, ICE_T, EM2_T, BRAKE_T}


I'm looking for a solution in this form:







I try to solve this equation using pdsolve but there is no results.

Eq:=diff(u(t,x), t$2) =diff(u(t,x),x$2)+sin(u(t,x));


Thank you for your help.


Hai everyone. I used maple 12 and have an equation as follow:

int(int(lambda[v]*lambda[t]*exp(-lambda[v]*v-lambda[t]*t), v = (1/2)*(q[p]+q[p]*t[c]*t+2*S[di]*h*t)/(h*t) .. infinity), t = 0 .. infinity)


and try to get an outcome as follow:

However, I cannot get the outcome like I want. The maple just diplay the equation. Any tips or suggestion?




What is the weak solution integral equation for 

du(x)/dx2 -(1+x2 ) u(x)-1=0


Maple needs 827 characters to write a equation of a straight line.
Is that true or what am I doing wrong?   

Can anybody help me or give a direction to handle with such problems?

  assume(2<alpha , alpha<=4);about (alpha);
before it does not help either.


Hi all

In matlab software we have a command namely fmincon which minimizes any linear/nonlinear algebric equations subject to linear/nonlinear constraints.

Now my question is that: what is the same command in maple?or how can we minimize linear/nonlinear function subject to linear/nonlinear constraints in maple?

thanks a lot

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department


What is the reason/Why: 


Error, (in dsolve/numeric/bvp) unable to achieve requested accuracy of 0.1e-5 with maximum 128 point mesh (was able to get 0.66e-1), consider increasing `maxmesh` or using larger `abserr`

Thanks for the help :)

The equation

x^7+14*x^4+35*x^3+14*x^2+7*x+88 = 0

has the unique real root

x = (1+sqrt(2))^(1/7)+(1-sqrt(2))^(1/7)-(3+2*sqrt(2))^(1/7)-(3-2*sqrt(2))^(1/7).

Here is its verification:

Is it possible to find that in Maple? I unsuccessfully tried the solve command with the explicit option.




Hi ,

I would like to resolve the Kortweg and de Devries equation :

> KDV2:= diff( u(X,T), T)+ 6*u(X,T)*diff(u(X,T),X)+ diff(u(X,T),X$3);


I used pdsolve but I have a problem to enter the IBC :

I want

u(infinity, t) =0
u( -infinity, t )=0

u ( x, 0 ) = 1

So I did :

> SOL:=pdsolve(diff( u(X,T), T)+ 6*u(X,T)*diff(u(X,T),X)+ diff(u(X,T),X$3)=0,{u(-10, T) = 0, u(10, T) = 0, u(X, 0) =1},numeric,time=T,range=-10..10);


But it doesn't work.

( I remplace infinity by 10 because then I want the graphic representation of the solution )

Could you help me please ?  

When trying to solve a set of partial differential equations, I always get the following error. I don't know what it means. Can somebody help me?


First 7 8 9 10 11 12 13 Last Page 9 of 25