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I need to plot M vs phi from the following ode. For this I am using implicitplot but unfortunately

I am getting empty plot. Please guide me through this issue.


eq1 := 1/(1-phi)^2.5/(1+4117/783*phi)*diff(f(eta),`$`(eta,3))+1/2*f(eta)*diff(f(eta),`$`(eta,2))

+M*(1-diff(f(eta),eta)) = 0;



Hi all,


I have a strange problem with the Classic worksheet in maple 15. To explain the problem i added an image.

when i want to plot vergl_6 without copying the equation i get an error. But when i just copy and paste equation 6 like i did everything works like i suspect.

Can anybody tell me the problem? I need to...

I adopted the approach suggested in an earlier post (

/questions/137320-Plotting-A-System-Of-Ode) for the known results,

but some part of curve is missing.

The output I got is


     So I've got a numerical solution to a D.E. and want to find which parameters (v, theta) cause the second event to occur. Here's my dsolve

> soln:= dsolve({eqx, eqy, inty, intx, x(0)=0, y(0)=0}, {x(t), y(t)}, numeric, method = rkf45, output=listprocedure, parameters=[v, theta], events=[ [ [diff(y(t),t)=0, y(t)

 The first event is "Does the trajectory reach its max at a height less than 3.05m? If so, stop computation"...

Hello every one,

I am using similarity transformation to transform a PDE into an ODE.

I got the ode but its in a very ambiguous (unclear) form.

I need help to have the ode in a more friendly reading format.



     I wish to plot the trajectory of a ball, and I set up my three differential equations and solved them numerically. I can graph the x, y, z components but I can’t figure out how to plot 3D space curve of this (and animate it if possible).

I used dsolve, numeric rtk45, so the output is [t, x, x’, y, y’, z, z’] so I tried to assign the second (and 4rth and 6h) term in the list to a function

i got error while running the code. 

restart; de := diff(f(y), y, y, y, y)+2*W*(diff(f(y), y, y, y))^2+3*(diff(f(y), y, y, y, y))*(diff(f(y), y, y))-(M*M)*(diff(f(y), y, y))+G*(diff(theta(y), y, y))+B*(diff(phi(y), y, y)) = 0, diff(theta(y), y, y)+Nb*(diff(theta(y), y))*(diff(phi(y), y))+Nt*(diff(theta(y), y))^2 = 0, diff(phi(y), y, y)+Nb*(diff(theta(y), y, y))/Nt = 0, f(h1) = (1/2)*F, f(h2) = -(1/2)*F, (D(f))(h1) = -1, theta(h2) = 1, phi(h2) = 1, (D(f)...

Hello every one,
I got an error while trying to solve numerically a nonlinear system of odes using 
the dsolve command. This error is very common,
"Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging".
I tried the different technique explained in

i have a differencial equation and use DEplot but it does't plot anything.

i have uploaded an image of what im doing


This question was asked before but because of the curiosity, I 

bring it in the light again. We have a system of odes


a := 1; b := .5; d := 1; omega := .4; h1 := 1+a*cos(x); h2 := -d-b*cos(x+omega);

F := Q-1-d;

de:={alpha*(diff(f(y), y, y, y, y))+G*(diff(theta(y), y, y))+B*(diff(phi(y), y, y))

+6*beta*(diff(f(y), y, y))*(diff(f(y), y, y, y))^2+3*beta*(diff(f(y), y, y, y, y))*

(diff(f(y), y, y))^2 = 0,

Hello every one,

I am trying to solve a system of 5 odes numerically but I get an error

"unable to convert to an explicit first-order system".

Please have a look and guide me through the problem.


For example 

y'''-y''+2y'=0 ; y(0) = 1, y'(0)=0, y''(0) =0
ode := diff(f(x), x, x, x)-(diff(f(x), x, x))+2*(diff(f(x), x))
the I.C. for y''(0) =0 is ?
Please give the format.
After numerically solving an ODE, I want to save the solutions as a .dat file. I got this from the internet net for PDES and tried by adapt it to odes using dsolve. But I get this: Error, `sol` does not evaluate to a module 
PDE := diff(u(x, t), t, t)-(diff(u(x, t), x, x))+.2(diff(u(x, t), t))-1/2*(u(x, t)-u(x, t)^3) = 0;
 IBC := {u(-15, t) = -1, u(15, t) = 1, u(x, 0) = tanh(x), (D[2](u))(x, 0) = -1/cosh(x)^2}; sol := pdsolve(PDE, IBC, 'numeric', u(x, t...

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)}|
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