Items tagged with differential_equation differential_equation Tagged Items Feed

ds(t)/dt = a*s(t)*(1 - s(t) - m(t)) - b*s(t) 

dm(t)/dt = c*s(t) - d*m(t)

 

need to find steady state of this system ( finding this simultaneously) in maple 

 

How can you do it? 

hello , to solve a differential euqations , maple gave me this error. please help me.

 

TG.mw

hello dear freinds

im new comer in maple.

i want to find  particular solution of an ode by following code:

ode := diff(u[1](t), t, t)+u[1](t) = -(1/4)*a^3*cos(3*beta[0]+3*t)-(3/4)*a^3*cos(beta[0]+t)

m := combine(convert(particularsol(ode), trig))

but maple solution is : m := u[1](t) = (81/32)*a^3*cos(-3*beta[0]+t)-(81/16)*a^3*cos(3*beta[0]+t)-(3/8)*a^3*t*sin(beta[0]+t)+(3/16)*a^3*cos(-beta[0]+t)-(27/16)*a^3*cos(beta[0]+t)+(1/32)*a^3*cos(3*beta[0]+3*t)

but  particular solution is :

u[1](t) = -(3/8)*a^3*t*sin(beta[0]+t)+(1/32)*a^3*cos(3*beta[0]+3*t)

is there any idear for finding the solution?

thanks in advance

Hey, how is can i see all the steps in maple? I would specially like to know it for differential equations.

For example we could use this one:

dl := 3*(diff(y(t), t, t))+6*(diff(y(t), t))+4*y(t) = 0 

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.

Dear all,

I am trying to find the intial velocity of a ball that is shot under an angle while only the start and end coordinates are given. The air resistance should also be taken into account. 

In order to do that I have build the following Maple sheet:

Assignment_question_1.mw 

I have used two differential equations that both include the variables v0 and t, and then try to solve them. Only I receive an answer in the form of RootOf, which I cannot remove with for example allvalues. 

I have been working for quite a long time on this but I am not coming any further, so is there anyone who can find what I am doing wrong/what I should be doing else? Or maybe my whole approach is not right?

Even a small step in the right direction would be appreciated a lot!

Thanks in advance,

Elise

Please, how do i compute,solve and derive d' Alembert wave formula with maple since wave=How do i derive d'Alembert formula using maple and also how to solve any wave problems eg IC u(x,0)=1/2e^-x^2 and ut(x,0)-e^-x^2 when c=4

I want to get numerical solution of the Eqs.ode(see the folowlling ode and ibc)in Maple.However,when i run the following procedure,it prompts an error "Error, (in dsolve/numeric/bvp) cannot determine a suitable initial profile, please specify an approximate initial solution". How to solve the issue? Please help me.


restart:
n := 1.4; phi := 1; beta := .6931; psi := 1

> restart;
> n := 1.4; phi := 1; beta := .6931; psi := 1;

> s := proc (x) options operator, arrow; evalf(1+(phi*exp(beta*psi)*h(x))^n) end proc;

> Y := proc (x) options operator, arrow; evalf(f-(1/2-(1/2)/n)*ln(s(x))+2*ln(1-(1-s(x))^(-1+1/n))) end proc;


> ode := diff(h(x), `$`(x, 2))+(diff(Y(x), x))*(diff(h(x), x)+1) = 0;


> ibc := h(0) = 0, ((D(h))(10)+1)*s(10)^(-(1-1/n)*(1/2))*(1-(1-1/s(10))^(1-1/n))^2 = 0;

> p := dsolve({ibc, ode}, numeric);
Error, (in dsolve/numeric/bvp) cannot determine a suitable initial profile, please specify an approximate initial solution
>

solve Differential equation "a-y=y' bc" use maple 17

the result is y(x)=a+_C1e^-(1/bc)

but the correct result  isn't y(x)=a-_C1e^-(1/bc) ?

Thank you in advance for your help

 

please help me to find an analytical approach to the below equation:

> ode3 := diff(n(t), t)+(1/2)*(-(3.707186000*(0.815e-1*(diff(n(t), t, t))+diff(n(t), t)))/(0.815e-1*(diff(n(t), t))+n(t))^(3/2)-(.1428*(1+0.714e-1*n(t)))*(diff(n(t), t)))/sqrt(7.414372/sqrt(0.815e-1*(diff(n(t), t))+n(t))-(1+0.714e-1*n(t))^2)+n(t)+sqrt(7.414372/sqrt(0.815e-1*(diff(n(t), t))+n(t))-(1+0.714e-1*n(t))^2)-(2.518891688*(1+.3570*n(t)))*sqrt(0.815e-1*(diff(n(t), t))+n(t)) = 0;
                                                                           /
                                                                           |
/ d      \                                 1                               |
|--- n(t)| + ------------------------------------------------------------- |
\ dt     /                                                           (1/2) |
               /           7.414372                                2\      |
             2 |------------------------------- - (1 + 0.0714 n(t)) |      |
               |                          (1/2)                     |      \
               |/       / d      \       \                          |       
               ||0.0815 |--- n(t)| + n(t)|                          |       
               \\       \ dt     /       /                          /       
              /       / d  / d      \\   / d      \\
  3.707186000 |0.0815 |--- |--- n(t)|| + |--- n(t)||
              \       \ dt \ dt     //   \ dt     //
- --------------------------------------------------
                                     (3/2)          
           /       / d      \       \               
           |0.0815 |--- n(t)| + n(t)|               
           \       \ dt     /       /               

                                        \       
                                        |       
                              / d      \|       
   - 0.1428 (1 + 0.0714 n(t)) |--- n(t)|| + n(t)
                              \ dt     /|       
                                        |       
                                        |       
                                        /       

                                                           (1/2)
     /           7.414372                                2\     
   + |------------------------------- - (1 + 0.0714 n(t)) |     
     |                          (1/2)                     |     
     |/       / d      \       \                          |     
     ||0.0815 |--- n(t)| + n(t)|                          |     
     \\       \ dt     /       /                          /     

                                                             (1/2)    
                                   /       / d      \       \         
   - 2.518891688 (1 + 0.3570 n(t)) |0.0815 |--- n(t)| + n(t)|      = 0
                                   \       \ dt     /       /         
> ics := n(0) = 0, (D(n))(0) = 674.5142595;


thanks and regards

louiza

 

AOA... Dears! When i solve the following differential equations

-(diff(lambda(s), s))-2*(diff(lambda(s), s, s))-(diff(lambda(s), s, s, s)) = 0

i got

lambda(s) = _C1+_C2*exp(-s)+_C3*exp(-s)*s

 here _C1,_C2 and _C3 are constant of intergration but i want the constant of integration of the following type

C[1],C[2] and C[3]

due to some reson pl help

Hi, I have a homework to do that I am strugling with:

write a procedure which uses euler's method to solve a given initial value problem.
the imput should be the differential equation and the initial value.
using this programme find y(1) if dy/dx= x^2*y^3 and y(0)=1, and use maple dsolve command to check the solution.

That is what I have managed to do, but somehow it is not working correctelly, can somebody help please?

eul:=proc(f,h,x0,y0,xn)
  local no_points,x_old,x_new,y_old,y_new,i:
  no_points:=round(evalf((xn-x0)/h)):
  x_old:=x0:
  y_old:=y0:
 
  for i from 1 to no_points do
      x_new:=x_old+h:
      y_new:=y_old+evalf(h*f(x_old,y_old)):
      x_old:=x_new:
      y_old:=y_new:
  od:
  y_new:
end:


Thanks

I'm trying to plot the direction field of the second order differential equation x''=x'-cos(x) using dfieldplot: 

> with(DEtools); with(plots);
> f1 := (x, y) options operator, arrow; diff(x(t), t)-cos(x(t)) end proc;
/ d \
(x, y) -> |--- x(t)| - cos(x(t))
\ dt /
> dfieldplot([diff(x(t), t) = y(t), diff(y(t), t) = f1(x(t), y(t))], [x(t), y(t)], t = -2 .. 2, x = -2 .. 2, y = -2 .. 2);
Error, (in DEtools/dfieldplot) cannot produce plot, non-autonomous DE(s) require initial conditions.
>

The error I'm getting says I need initial conditions, but I wasn't provided with any. Is there another way to plot this? Sorry if this is dumb question, but I've only ever plotted first order equations.

I have to solve a system composed of a mass, a spring and a damper, represented by this equation :

m (d2x/dt2) + c (dx/dt) + k x(t) = F(t)

with m the mass, t the time, c the constant of the damper, k the constant of the spring, F an external force applied to the mass and x(t) the movement of the mass m at time t.

Please help me to solve this equation on Maple.

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