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I'm trying to use Maple to assist me in my homework.  To me, TI & MsMath are more intuitive than Maple, however, i have a Maple license.  That said, how do i specify an initial condition while trying to solve an ODE using dSolve?  For TI, i would enter:

deSolve(x’=x/25 and x(0)=20,t, x)

... and be done with it.  I suspect that i have to use diff() to assign x/25 as the f(x) of y'.  However, how do i specify the initial condition?

I want to solve a diff eqn, but it is giving absurd answer.

> ode := diff(f(x), x, x) = (Phi(x)-lambda)*f(x);
d / d \
--- |--- f(x)| = (Phi(x) - lambda) f(x)
dx \ dx /
> dsolve(ode);
/ / / d / d \\\ \
f(x) = DESol|{ (-Phi(x) + lambda) _Y(x) + |--- |--- _Y(x)|| }, {_Y(x)}|
I am dealing with a problem in engineering mechanics, but my when using maple to solve the governing nonlinear equation with 4 bcs, I meet with error. 
Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging

my code is :
deq := diff(y(x), `$`(x, 4)) = -.364*(diff(y(x), x))^2*(diff(y(x), `$`(x, 2)))+1.74*10^(-7)
bc := y(0) = 0, (D(y...

I am new to maple. The problem I am facing is to get a non-trivial

solution of a system of odes. But maple gve me only trivial solution.

 

# The system of odequations I am trying to solve is (Please note that in the bcs phi is alpha.)

 

 

# The solution of the above sys of odes is of the form, (note x3=z, its just a typo)

How can I use the command outputs DEtools [convertsys] for solving the system of differential equations? I know that maple can solve the system directly. But most of the examples can be seen in other systems (MathCad, MatLab ..) reduce the system to a system of first order equations. And I would like to implement, "translate" into Maple in this way. Is there a command that allows it? Do I need to implement a procedure?

GRACIAS

Hi

I am a PhD scholar at the University of Queensland. I am reviweing a paper titled as "A similarity solution for laminar thermal boundary layer over a flat plate with a convective surface boundary condition"(the pdf is available online). In this paper the author has written a MAPLE code. I copied the same code in MAPLE but could nt succedded. The author used the Runge Kutta RK5 Method to solve the model.

Please help me to solve the same model...

hi

consider the following ode

eq1:=diff(f(x),x$3)+f(x)*diff(f(x),x$2)+diff(f(x),x$1)^2;

subject to thease boundary condition

f(a)=0,D(f)(b)=0,D(D(f))(0)=0

where

b= infinity (in computational domain b=10 is acceptable )

the exact solution of ode is

f(x)=tanh(x/2)

but when i want to solve it with Dsolve, maple get the zero. how can i use this ode in maple

 

thanks

Hello,

I have a system of two ODEs.  The solutions of the system (U(t) and V(t)) should never take on negative values, but may approach zero.  When using dsolve (numeric) to solve the system and odeplot to plot the system, I can see that dsolve gives slightly negative values to the solutions when close to zero.  This may result in the solutions becomes increasingly negative over time.

How can I prevent dsolve from assigning negative values to...

Solve the equation y"-4y=lnx ?

                                     

hi

i write the followinf code in maple

eq1:= f'''(x) - f'(x)

is this posible in maple that i worte the above command like this

Linear:= d3/d(x) - d/d(x)

eq1:= linear (f)

thanks for youe attention in advance

I want to solve a set of ODE equations numerically,there is 5 equations with certain boundary conditions,please help me,what kind of dsolve order could i use? when i use dsolve({sys,bcs}type=numeric) i get an error that say me:system must be entered as a set of equations! how can i solve it?

Hello,

I'm having problems to do somehting that I guess maple should be able to do. I am solving numerically a 2nd order equation. Then Dsolve gives me the function and its first derivative.

Is there not a way to plot 2nd and 3rd derivatives??
Of course I have thought of getting f'' as a funtion of f' and f through the differential equation, but in my case that involves a complicated analytical development, and I precisely want to verify that I didnt do...

Hi,

 

Is there a way to generate Java or C code to implement a general nth order linear ordinary differential equation?

I am looking to be able to send the coefficients and have it compute the time waveform given initial conditions.

 

Regards.

i am looking for a command adjoint a ODE, to check whether my understanding of adjoint correct or not, when i find one example different from my understanding as follows

u*diff(Y,t) - diff(U,t) + diff(y,t)*U = 0 where uppercase and lowercase are different

why after adjoint is

Y -> -u*diff(lambda,t) - diff(u,t)*lambda = miu1
U -> diff(lambda,t) + diff(y,t)*lambda = miu2

why not

Y -> u*diff(lambda,t) = miu1
U -> -diff(lambda,t) + diff(y,t)*lambda = miu2

Okay, so I think this is simple, but I cannot find the command.

 

I get a numeric solution for a system of ODEs, with variables a function of t. Now, I know I can use the sol(t) command to give me the values of my variables at specific values of t. But, how do I get the values of t for specific variable values. There has to be a more efficient way than just plugging in values for t until I come to the answer.

Thanks!

 

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