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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?

 

Hi there,

I'm quite new to Maple so please forgive me! I have a system of partial differential equations I'm trying to solve in Maple as such below 

 

df/dt = f(1-f) - f * h

dg/dt = g(1-g) * Gradient(1-f * gradient(g))

dh/dt = (g - h) + Laplacian(h),

where f,g,h are functions of space and time (i.e. f(x,y,z,t)). I guess my first question is - is this possible in Maple to evaluate? (I'm currently unsure on ICs as I'm figuring it out from the model - it's a model for cancer growth I'm trying to evaluate but have a rough idea of what I'd use).

If it is possible, can you please share how I'd write this? Everytime I've tried I seem to be failing to define anything properly, so your expertise would be greatly appreciated!

I am trying to illustrate the chain rule for multivariet functions

 

diff(f(u(x,y),v(x,y),x)

 

The Maple responce is D1(f)(u(x,y),v(x,y)*(partial of u(x,y) wrt x) +..etc

 

I would like to replace the D- notation with the standard notation for the "partial of f wrt u" for obvious reasons - this is what students are familar with. The convert cmnd Doe Not Work in this case.

 

Similarly the cmnd diff(u(x,y),v(x,y),x,x) gives rise to D1,D11, D12 symbols which I would likee to convert to standard partial notation.

 

All this is a BIG DEAL when trying to illstrate the chain rule in Cal III.

 

Joe Salacuse

Mathematics

Kettering University

Hello;
        i am wording on fluid dynamics, in which i can up a system of nonlinear partial differential equation with i am suppose to solve using implicit keller box method. i need an asistance on how to implement this in maple.

i have got alot of mixed and high degree derivatives. For example:

u[x]*u[x,t]*eta[x,t]+u[]^2*u[x]*eta[x]+kis(x,y)u[x,t]^2*u[]+eta(x, y)*u[]*u[x]^2+ksi[x,t]*u[x]^2*u[x,t]+......

like this alot of terms

my question is how can i solve divided by the derivative of the u(x,t) partial differential equations system and so  how can i find eta(x,t,u) and ksi(x,t,u) 

Hey everybody I am trying to get maple to do some partial differention for me. 

Where 

 

I have PDEtools on but, it doesnt return an expression correctly. It's I think the problem is because Ψ is a function of (x,y) and f is a function of η and η is a function of x and y . U and ν are constants. vand vy are the x and y velocites. 

 

What I would like the program to return when I write 

is something along the lines of 

 

could someone give me a hand on this. I would really apperciate it. 

 

Best Regards, 

Kyle 

Hi, I am looking for some help for a computation on Maple. I have the following objects

Hello,

I'm trying to solve the effects (deflictions, tensions, etc) of a load on a timoshenko beam. It uses two partial diffential equations, wherein q is the load:

> PDE1 := kappa*G*A*(diff(y(x, t), x, x)-(diff(theta(x, t), x)))-rho*A*(diff(y(x, t), t, t))-q;

> PDE2 := E*J*(diff(theta(x, t), x, x))+kappa*G*A*(diff(y(x, t), x)-theta(x, t))-rho*J*(diff(theta(y, x), t, t));

The boundary conditions are that in the corners the moments (derative of theta...

Non-linear PDE problem...

December 04 2012 puzzles 0
Hey everyone. The last few days I work on a non-linear PDE. 
U*`∂`(F(s))/`∂`(x) = -k*sigma*cos(theta)*`∂`(F(s)*kro(s)*`∂`(J(s))/`∂`(x))/(`μo`*sqrt(k/phi)*`∂`(x));
with boundary conditions: when x=-∞: s=swi       and  
x=L : U*dF(s)+k*sigma*F(s)*kro(s)*`∂`(J(s))/(`μo`*sqrt(k/phi)*`∂`(x))
I need to plot...

How can I see the steps of solving a PDE ( partial differential equation ) in maple .
for example see the sepration variables and other equations that lead to final Eq .

how can i solve pdes of the following form in maple

[tex] tc(t,x)\frac{\partial a(t,x)}{\partial t} - ta(t,x)\frac{\partial c(t,x)}{\partial t} = a(t,x)c(t,x) + t(a(t,x))^2 and be able to find both functions a(t,x) and b(t,x)

restart

u := proc (x, y) options operator, arrow; u[x](x)*(y/delta(x)-2*y^2/delta(x)^2+y^3/delta(x)^3+B*H*(1-3*y^2/delta(x)^2+2*y^3/delta(x)^3)/delta(x))/(3*B*H/delta(x)+2) end proc

int(u(x, y)^2, y = 0 .. delta(x))

 

I tried the following partial integration in MAPLE. But Maple says:

Error, (in u[x]) too many levels of recursion.
Analytically it is possible to evaluate the integral in the above lomits. Where lies the problem?

 

Dear my friends

Hi

I have a linear partial differential equation to solve.

> equ1:=F5*(diff(phi[2](r, theta), r, r)+(diff(phi[2](r, theta), r))/r+(diff(phi[2](r, theta), theta, theta))/r^2)+F3*phi[4](r,theta) = 0;

where F5 and F3 is constant and phi[2](r,theta) is unknown function.

I tried to solve this equation by the following Maple's command:

> pdsolve(equ1,phi[2](r,theta));

I'm having a few problems with differentiating in Maple. I have a potential function U given by:

U[c] := (1/2)*r^2+M[1]/r[1]+M[2]/r[2];

U[r] := r^2*(M[1]*M[2]-3)/(2*c^2)+((x(tau)+diff(y(tau), tau))^2+(y(tau)-(diff(x(tau), tau)))^2)^2/(8*c^2)+3*(M[1]/r[1]+M[2]/r[2])*((x(tau)+diff(y(tau), tau))^2+(y(tau)-(diff(x(tau), tau)))^2)/(2*c^2)-(M[1]/r[1]+M[2]/r[2])^2/(2*c^2)-M[1]*M[2]*(1/r[1]+(1/r[1]-1/r[2])*(1-3*mu-7*x(tau)-8*(diff(y(tau), tau)))+y(tau)^2*(M[2]/r[1]^3+M[1]/r[2]^3))/(2*c^2);

I have a nonlinear partial diff eq which I am sure has been categorized.  How do I go about finding literature on the eq & the approach to solve it.  I have visited various websites that have catalogs of nonlinear partial diff eq's.  The problem is notation is so NONSTANDARD I have no IDEA what I am reading.  I have included a PDF eq_of_choice.pdf with my notation which I am familiar with. ...

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