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 Have to solve and ODE in the domain of [-infnity +infinity ] via specific analytical method but due to some restrictions it could not be solved. In order to solve it, I have separated the domain into [-infinity 0 ] and [0 infinity]. So, I have to add some boundary values at x=0 to the problem. Assuming the solution of the mentioned ODE in  [-infinity 0 ] is g(x) and in [0 infinity]  is f(x), I added the boundary values of f(0)=g(0)=a and f ' (0)=b and obtained f(x...

i came into some questions when i wanted to solve a pde systerm as follows:

> pde := diff(u(x, y), y, y, y, y) = 0;
> sys := [pde, u(x, 0) = 0, u(x, a) = F0, (D[`$`(2, 2)](u))(x, 0) = 0, (D[2, 2](u))(x, a)-beta*(D[2](u))(x, a) = 0];
> pds := pdsolve(sys);
%;
Error, (in pdsolve/sys/info) found functions with same name but depending on different arguments in the given DE system: u(x, a), u(x, y). It is required an indication of the dependent variables

Hello all, I am wondering if anyone knows how to impose a finite value boundary condition to solve an ordinary differential equation? Specifically, suppose that the solution Maple obtains to an ordinary differential equation is y(x)=-2*x^2+C1*ln(x), C1 being a constant. Given that y(x) must be finite when x=0, then C1 has to be zero. Is there a way to implement this condition when setting up to solve the ODE in Maple, i.e. dsolve({ODE, ICs}, y(x), options)? Many thanks for your help!

i'm trying to solve a sysem of pde, but i get this error 

Error, (in PDEtools:-Library:-NormalizeBoundaryConditions) unable to isolate the functions {x(0, z, r), x(t, z, 0.5e-2), xeq(t, z, 0.5e-2), y(0, z, r), y(t, 0, r)} in the given boundary conditions {x(0, z, r) = 0, x(t, z, 0.5e-2) = xeq(t, z, 0.5e-2), y(0, z, r) = 0, y(t, 0, r) = 0}
> 

> restart; with(PDEtools);
[CanonicalCoordinates, ChangeSymmetry, CharacteristicQ, 

  CharacteristicQInvariants,...

I have a region x^2 + y^2 <= 1 and y>=0. It's temperature function is f(x,y) x^2 - 2y^2 + x + y. How do I find the max and min temperatures on the lower boundary y=0?

I took the derivatives with respect to x and with respect to y such that:

fx:=diff(f(x,y),x);

fy:=diff(f(x,y),x);

Then I used fsolve({fx=0, fy=0},{x,y}) which game me (-0.5, 0.25)

Is there really only one critical point on that lower bound...

I tried to solve a non linear coupled boundary value problem in MAPLE using DSolve command. The code is :

alias(eta = e, theta = t)

Eq[1] := 5*(diff(F(e), `$`(e, 3)))+(m+3)*F(e)*(diff(F(e), `$`(e, 2)))-(2*m+1)*(diff(F(e), e))^2-(4*m+2)*H(e)-(m-2)*e*(diff(H(e), e)) = 0

Eq[2] := diff(H(e), e) = t(e)

Eq[3] := 5*(diff(t(e), `$`(e, 2)))/Pr-(m+3)*F(e)*(diff(t(e), e))-5*m*(diff(F(e), e))*t(e) = 0

BCs := [F(0), (D(F))(0), (D(F))(infinity), t(0)-1, t(infinity), H(infinity)]

I was trying to solve a PDE with boundary conditions and maple 15 didn´t give no answer. 

Is there something wrong? I'm just trying to solve a textbook problem om electrodynamics in maple.

Hi. Solving a problem of non-linear oscilations of thin string I met a PDE with unusual bcs at the right side of the string: 
 , where phi is known function. Can...

Hi

I'm solving a differential equation which has a boundary at infinity, when I add this third condition it returns nothing. Of course I it's easy to solve by hand but it should be done in a loop. can you give me a hint on this?

Thanks

Hi all,

I have a set of two coupled PDEs and Maple keeps giving me invalid initial/boundary conditions. I really don't know how to fix it. Attached is my worksheet. Please help me out.

Thank you

2dcase.mw

Hi,

I am trying to solve the following system of ODE's given some initial and final conditions.

Hello,

I am going to solve 2D Laplace equation for function Φ(x,y) in a rectangule which has a*b dimension, yet its boundary condition, at least for me, is rather complex. Here it is:

d/dx(Φ)=0  at  x=0 , x=a

Φ=1  at  0<x<a/2 , y=0   

d/dy(Φ)=0  at a/2<x<a , y=0

Hi,

I am trying to solve a system of PDEs numerically and having following error

Error, (in pdsolve/numeric/plot3d) unable to compute solution for t>HFloat(0.0):
solution becomes undefined, problem may be ill posed or method may be ill suited to solution

Please have a look at attached worksheet and help me out.

Moreover, I want to include boundary conditions are not normal to the boundary. Anyone knows how to do so? Any help would be appreciated.

independent.mw

initial/boundary conditions can only contain derivatives which are normal to the boundary

I got this message when trying to solve a system of three PDEs numerically. Does anyone knows what it mean? Thanks.

newlam