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Hello all, 

During my last attempt to solve ODE system (autonomous system which includes 3 first order diff. equations) with initial conditions, Maple had performed the solution which includes d_z1 parameter as follows below (I present the solution of one of the equations):

S(t)=S(0)∫(QN_z1+A)d_z1, where integral ∫ is defined integral from 0 to t, S(0) is the initial value of S, Q, N and A are the parameters. I would like to ask, what does it mean _z1 and d_z1? Why if the ODE system is only time dependent, I received the integral with other differential, that is d_z1? Does it mean that the integral can't be evaluated or maybe something else?

Thanks in advance,

Dmitry

 

 

Hey all new to Maplesoft my question is this;

2. Give the Maple command(s) to compute \frac{\partial^8 f}{\partial^5 x \partial^3 y} for f(x, y) = e^{2x+ cos(y)}.

The goal is to get Kalman Form

https://docs.google.com/file/d/0Bxs_ao6uuBDUT25BeVhtWjZwRUU/edit?usp=sharing

https://docs.google.com/file/d/0Bxs_ao6uuBDUVXU5dXh6Rl9zUUU/edit?usp=sharing

 

I am doing the example in page 707 of Partial Differential control theory Volume 2 by J.F.

 

when using Robertz Daniel's Ore and Involutive packages

 

with(Involutive):

with(OreModules):

Alg := DefineOreAlgebra(diff=[D,t...

Diff(x1(t),t) - x2(t) = 0;

Diff(x2(t),t) - x3(t) = 0;

Diff(x3(t),t) +3*x3(t) + 4*x2(t) + x1(t) = 2*Diff(u(t),t$2) + 5*Diff(u(t),t) + 7*u(t);

 

multiply above system by test functions -lambda1(t),-lambda2(t),-lambda3(t) and integrate by part

in order to find adjoint operator in the form

 

x1 -> Diff(lambda1(t),t) - lambda3(t) = miu1(t)

x2 -> Diff(lambda2(t),t) + lambda1(t) - 4*lambda3(t) = miu2(t)

Can maple use a Differential Operator somehow in the following sense?

Instead of expanding (D-p)^n where p is a constant and D the differential operator and n an integer and then in each term writing D^n(f) for some function can I just leave the expression as it is like

(D-p)^n and acting on everything on the right?

Hi every body

I want to solve a differential equation y'(t) = sqrt((f-1)/(t^f-t)) and get an answer in terms of ordinary function.is it possible. thanks 

Hi,

I'm searching for the third differential equation that will transform the following two equations non-autonomous system into a three equations autonomous one:

diff(x(t),t)=-x(t)+2*(m*t+n)*y(t)-2*k*(m*t+n)2

diff(y(t),t)=-y(t)+k*m-(m*t+n)*((x(t)/2)-1)

 

diff(z(t),t)= ...

 

Regards,

Johnny

     Many times when I use dsolve to find the solution of an equation like x-y/y' = y , I get a term involving the LambertW function.  However, the equation has homogeneous coefficients for dx and dy, so it can easily be solved by substituting y=u*x and separating the variables.  The closed form solution of the above is x+y*ln(y)+c*y = 0 , but I cannot get that answer from Maple.  Is there...

Hello, 
I'd like to identify terms before the differential terms (theta(t), diff(theta(t),t) ...)

The following code with coeff function works for  diff(theta(t), t, t)) but not for diff(theta(t), t)
Here the code :
eq1pp := R(t) = -(-sin(theta[0]+phi)*Isup-sin(theta[0]+phi)*L[fixe]^2*M[fixe]-sin(theta[0]+phi)*L[r]^2*M[r]-sin(theta[0]+phi)*L[sup]^2*M[sup]+cos(theta[0]+phi)*a*sin(phi)*L[fixe]*M[fixe]+cos(theta[0...

Hi all,

I am new to Maple and I have (possibly a simple) question. I'm solving 2 coupled differential equation, it all goes well, until I want to plot them.

I have the output in the following form:

sol = {w1(x) = [ -a*x^4+b*x^3-c*x]}, {w2(x) = [-d*x^4+e*x^3-f*x^2+gx-h]}

My goal is now to plot the solution in 1 figure with w1(x) between x=0..100000 and w2(x) between x=100000..150000

I have searched on the web for a way to get the formula's of w1(x...

I'm solving a system of ordinary differential equations numerically, I used the dsolve(system,numeric) to do it. I have also plotted the solutions. Now I want to know where does this solution cross zero and use this value for later computations, is there a way to do it? 

This question is, as I think, equivalent to how to find the roots for a curve expressed in numerical arrays.

Thank you!

I know how to solve system of differential equations numerically, but now I want to know how to set a bound on the solutions. 

For example, if my system of DE is like this:   dx/dt = x+y   dy/dt = x-y    , solve x and y in t. 

I can solve this without any restriction on x and y, now I need to know how to bound x and y, e.g. x can only fall in the interval [0,1]

 

Thank you very much!

Hi all,


I must confess I'm a perfect novice in Maple as I'm used to work with Matlab. I have a 3d differential equation, namely:


dM/dt+gamma*mu[0]*`&x`(M, H[eff])-G/(gamma*M^2) *`&x`(M, dM/dt)= 0

The components of M should be of the form M_{i0} + dM_i(t) where M_{i0} is a constant and dM_i(t) a function of t, i = 1, 2, 3. And...

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