# Items tagged with odeode Tagged Items Feed

### convert second order ode to first order ode.......

October 30 2014
0 2

Hi every body:

i have a second order ode and will convert to two ode of first order with maple,how do this work???

eq := diff(y(x), x, x)+2*y(x)+y(x)^2 = 0

### Solving system of ODEs whose variables come in 2 p...

October 28 2014
0 1

Let N be an integer.

For each pair of integers (n,m) where 1<= n,m <= N, we have a variable f_{n,m}(t).

Then for these we have a system of ODEs

d/dt f_{n,m}(t) = \sum_{n', m'} f_m'n' * f_m''n'' * (m'n'' - m''n')

where m''=m-m', n''=n=n', and the sum is simply over for all pairs (n',m').

I simply do not know how to put these set of equations into Maple in a nice way.

I will really appreciate any help!

### Solving system of ODEs by Laplace transform...

October 11 2014
0 1

I'm trying to solve this system of ODEs by Laplace transform.

> de1 := d^2*y(t)/dt^2 = y(t)+3*x(t)

> de2 := d^2*x(t)/dt^2 = 4*y(t)-4*exp(t)

with initial conditions

> ICs := y(0) = 2, (D(y))(0) = 3, x(0) = 1, (D(x))(0) = 2

Using

> deqns := de1, de2

and

> var := y(t), x(t)

I need to solve it for both y(t) and x(t), I have tried this by:

> dsolve({ICs, deqns}, var, method = laplace)

And

> dsolve({ICs, deqns}, y(t), method = laplace)

> dsolve({ICs, deqns}, x(t), method = laplace)

However I get this error message:

Error, (in dsolve/process_input) invalid initial condition

Any help is appreciated

### Solving an ode : Warning, it is required that the...

October 10 2014
1 3

Hello,

could you help me solve this error ? I don't understand what it means.

> eq3:=diff(x(t),t,t)+Gamma*diff(x(t),t)+omega[0]^2*(x(t)-(diff(x(t),t,t)+Gamma*diff(x(t),t)+omega[0]^2*x(t)+omega[0]^2*X[0])/omega[0]^2) = -omega[0]^2*X[0]:
> dsolve(eq3);
Warning, it is required that the numerator of the given ODE depends on the highest derivative. Returning NULL.

Thanks.

### bifurcation diagram...

September 29 2014
1 0

Hi,

I have a non linear ode with sinosoial term, (sin(x)).

How can we Analyse the system and plot the bifurcation diagram:

x'=r*x-sin(x);

Thank you very much for your help.

### Homotopy Analysis Method...

September 26 2014
0 0

Hi

I have three system of ODE and i would like to solve it using Homotopy perturbation method. Could you please provide to me the code in Maple or the Maple pachage that used to solve it by Homotopy perturbation method ?

I hope to hear you soon

Sara

### Maple, code, saddle node bifurcation...

September 24 2014
1 3

Hi.

I need you to answer to thos question using maple,

I have x'(t)=e^{2*x(t)}  + alpha -2*x(t),  where alpha is a constant in R.

I would like to compute the equilibrium points and if there is a saddle-node bifurcation.

Thank you very much.

### How do I write maple programme for non-linear ode...

September 21 2014
0 1

Good day, can any one help in writing maple programme for the finite difference (FD) formulae define to solve this coupled non-linear  ODEs. See it here FDM_programme.mw Thank you

### Rearranging two ODE's...

September 10 2014
1 1

Hi I am simply trying to rearange equation X, the steoes I want to do are differentiate X w.r.t t then insert equation Y into the new differentiated form but I am stuck, I am not really sure what to try I have used algsubs but it comes up with an error.

here is my code:

X := diff(x(t), t)+(k1+k2+k3)*x(t)-(k4-k1)*y(t)-k1 = 0;
print(output redirected...); # input placeholder
/ d \
|--- x(t)| + (k1 + k2 + k3) x(t) - (k4 - k1) y(t) - k1 = 0
\ dt /
Y := diff(y(t), t)+(k4+k5+k6)*y(t)-(k3-k6)*x(t)-k6 = 0;
print(output redirected...); # input placeholder
/ d \
|--- y(t)| + (k4 + k5 + k6) y(t) - (k3 - k6) x(t) - k6 = 0
\ dt /
A := diff(X, t);
print(output redirected...); # input placeholder
/ d / d \\ / d \
|--- |--- x(t)|| + (k1 + k2 + k3) |--- x(t)|
\ dt \ dt // \ dt /

/ d \
- (k4 - k1) |--- y(t)| = 0
\ dt /
algsubs(Y, A);
%;
Error, (in algsubs) cannot compute degree of pattern in y(t)

### Error in program...

September 09 2014
0 5

Hi all

I have written the following code in maple to approximate arbitrary functions by hybrid of block-pulse and bernstein functions but it doesn't work properly especially for f(t)=1.0, so what is the matter?

bb1.mws

best wishes

Ph.D Candidate

Applied Mathematics Department

### How could I know step by step Maple find Liouvilli...

August 23 2014
1 3

Hi

I'm dealing with 2nd order ODE on Maple. By using " infolevel 5" Maple tell me that it use Kovacic's algorithm to find the solution. Could anybody tell me how or at least some idea so that I can go on this my self. Following here my ODE

Thank you so much

Chaimongkol

### Find extremes of numeric solution of ODE system...

August 17 2014
1 1

Hello! How can I find extremes of numeric solution of ODE system obtained using "dsolve"? Can I use something like "extrema" function?

### ask for help on ODE solution...

August 15 2014
1 4

I failed to solve the ODE system shown as follows, where y1(x) and y2(x) are functions of x, ranging from -L/2 to L/2. All the other parameters are constants (A,B,C,F,G). The analytic or numeric solution of y1(x) and y2(x) are wanted.Really appreciate for you experts' help and time!!!

dsys:={diff(y1(x),x$2)-A*x^2*y1=B*diff(y2(x),x$3),diff(y2(x),x$2)-C*diff(y1(x),x)=F*x^2+G} boundary conditions:y1(0)=0, diff(y2(L/2),x$2)=0, D(y2)(0)=0, y2(L/2)=0

### solve the nonlinear ode equations...

July 22 2014
0 4

Hi:

i will solve the five nonlinear coupled odes with maple in least time,can evey body help me?

eq1:= -3515.175096*Pi*q[1](T)*q[4](T)-3515.175096*Pi*q[1](T)*q[5](T)-2650.168890*Pi^2*q[3](T)*q[1](T)-9.871794877*10^7*q[2](T)*Pi+.5622514683*(diff(q[1](T), T, T))+1.893468706*q[1](T)^3*Pi^4+2.507772708*10^5*q[1](T)*Pi^2=0

eq2:= 496.9066665*q[2](T)*Pi^2-380.5288665*q[4](T)*Pi-62694.31768*Pi*q[1](T)+380.5288665*q[5](T)*Pi+0.3570776400e-3*(diff(q[2](T), T, T))+2.467948718*10^7*q[2](T)=0

eq3:= 2650.168888*q[1](T)^2*Pi^2+7.824250847*10^5*q[3](T)*Pi^2+1.037806000*10^6*q[5](T)*Pi+.5622514682*(diff(q[3](T), T, T))+1.037806000*10^6*q[4](T)*Pi=0

eq4:= 63661.97724-241.8620273*q[1](T)*(diff(q[1](T), T))-6.792272727*10^6*(diff(q[4](T), T))-5191.348749*q[4](T)-5191.348749*q[5](T)+71406.36133*(diff(q[3](T), T))-6.792272727*10^6*(diff(q[5](T), T))=0

eq5:= 70.02817496+2490.500000*(diff(q[5](T), T))-29887.90351*q[4](T)+29887.90351*q[5](T)-2490.500000*(diff(q[4](T), T))-45.34913011*(diff(q[2](T), T))=0

### Warning, cannot evaluate the solution further righ...

July 09 2014
0 1

Pleaz i nees help i have probleme withe singularity

 >

Paramétres

 >
 (1.1)

Equation suivant x :

 >
 (2.1)

Equation suivant z :

 >
 (3.1)

Equation suivant y :

 >
 (4.1)

Equation suivant y

 >
 (5.1)

Résolution :

 > CI:= x(0)=0,z(0)=0,theta(0)=0,alpha(0)=0,D(x)(0)=0,D(alpha)(0)=0,D(z)(0)=0,D(theta)(0)=0;
 (6.1)
 > if theta(t) <> 0 then  solution:=dsolve([eq1,eq2,eq3,eq4,CI],numeric,maxfun=0):  odeplot(solution, [[t, x(t)]], t = 0 .. 100, thickness = 2);  odeplot(solution, [[t, z(t)]], t = 0 .. 100, thickness = 2);  odeplot(solution, [[t, theta(t)]], t = 0 .. 100, thickness = 2);  odeplot(solution, [[t, alpha(t)]], t = 0 .. 100, thickness = 2);  #odeplot(solution,[[t,x(t)],[t,alpha(t)],[t,z(t)],[t,theta(t)]], t=0..100, thickness=2);  end ;

thank you !