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is there a possibility to display the partial derivative of f(x,y) wrt. y as

and second order / cross-partials accordingly?

 

thx

jo

 

 

Is there a help page which explains why braces provide the partial text evaluation in this code?

RopeLen := 30;RopeAddLen := .5;

plots[textplot]([1, 1, typeset("%1", (({(1/2)*RopeLen}+{(1/2)*RopeAddLen})^2-{(1/2)*RopeLen}^2)^(1/2))])

Hi,

    i meet  a partial differential equation seems not complicated

with(PDEtools):

PDE := (diff(f(x__1, x__2, p__1, p__2), x__1))*p__1/m-(diff(f(x__1, x__2, p__1, p__2), p__1))*(2*k*x__1-k*x__2)+(diff(f(x__1, x__2, p__1, p__2), x__2))*p__2/m-(diff(f(x__1, x__2, p__1, p__2), p__2))*(-k*x__1+2*k*x__2);

when i use

     pdsolve(PDE);

i get nothing,but i sure

    f=c*(p__1^2/m+p__2^2/m+4*p__1*p__2/m+6*k*x__1*x__2) 

is the one solution of the differential equation .

how i can get solutions about of the above equation.

thanks .

 

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 entering into Maple, but it interprets it as

How do I change this partial derivative to a total one. (Both x and y can be assumed invertible functions of parameter u and their derivatives are nonzero)

Is it possible to somehow extract a derivative from numeric solution of partial differential equation?

I know there is a command that does it for dsolve but i couldn't find the same thing for pdsolve.

The actual problem i have is that i have to take a numeric solution, calculate a derivative from it and later use it somewhere else, but the solution that i have is just a set of numbers an array of some sort and i can't really do that because obviously i will get a zero each time.

Perhaps there is a way to interpolate this numeric solution somehow?

I found that someone asked a similar question earlier but i couldn't find an answer for it.

I'm trying to find the partial sum of the function. Now I need to plot the first couple partial sums onto 1 graph.

I'm not really sure how to input the plot function. I was able to graph it by inputting each partial sum function but I would prefer an easier solution.

Hi, I have a bivariate generating function that looks like this

x/((1-x)*(2-x-x^k))

where x is enumerating by binary strings by length and k is counting a number patterns in the string. I would like to convert the series into partial fractions. Convert[parfrac] only seems to work when k is given a value, which I did for several small small choices, from which I guessed the general partial fraction decomposition. Would someone have an idea on how to extract the partial fractions directly in terms of x and k?

Thanks,

best, Luke

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

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...

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)

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