Linked Questions

2 votes
1 answer
2k views

Finding power series solution for differential equation in Mathematica [duplicate]

I know this topic has been covered before, but I've tried all the solutions I can find from other users' questions and none of them have worked. I need to find a power series solution to the ...
user53707's user avatar
2 votes
2 answers
493 views

How to get the series coefficient of a function defined by a differential equation [duplicate]

I need a Taylor series approximation for $x(t)$, which is defined by the following differential equation. $\frac{dx}{dt}=-k_1 x+(1-x)k_2 e^{-k_3 t}$, $x(0)=0$ ...
Bravo's user avatar
  • 283
2 votes
1 answer
332 views

Solving for the coefficients of a series [duplicate]

Suppose I have a given series $A(z)=\Sigma a_nz^n$ I want to solve a differential equation for $B(z)$ in terms of coefficients of $a_n$ as a series. Possibly with ansatz $B(z)=\Sigma b_nz^n$ or other ...
Duke Smith's user avatar
1 vote
0 answers
625 views

Solving differential equations with sums (power series) [duplicate]

I have sets of 10 differential equations, but for this purpose I'll demonstrate what I need on one example that can be solved by hand. My equation is this: $$4GJ\Omega(\theta)\Omega'(\theta)\xi^\...
dingo_d's user avatar
  • 677
-1 votes
1 answer
384 views

How to find the power series solution of this ordinary differential equation using MMA [duplicate]

I already know that the solution of this differential equation $y''(x) - x*y(x) = 0$ can be expressed by the following power series: $$y(x)=c0(1+\frac{x^{3}}{2\times3}+\frac{x^{6}}{2\times3\times5\...
A little mouse on the pampas's user avatar
9 votes
3 answers
872 views

How do I find a series solution for $e^{-\frac{1}{2}f'(x)} \mathrm{cosh}( f(x) ) = ax + b$?

I am trying to approximate a function $f(x)$ satisfying a relation between $f(x)$ and its first derivative. How do I find a series solution for $$e^{-\frac{1}{2}f'(x)} \mathrm{cosh}( f(x) ) = ax + e^{-...
Quant's user avatar
  • 125
6 votes
3 answers
4k views

Solution of equation with power series (perturbation)

So I need to use Mathematica to find the solution of $y=x- \epsilon \sin(2y)$ as a power series in terms of $\epsilon$. I'd assume I'd need to create an equation $f=x-y- \epsilon \sin(2y)$, then ...
Lenny's user avatar
  • 61
10 votes
1 answer
982 views

Trouble with shooting method for a 4th-order differential equation

I'm trying to solve the following forth-order ODE with the shooting method: $$\frac{1}{5}(y-2xy^\prime)=\frac{1}{x}\left\{\frac{xy^\prime}{y}+xy^3 \left[\frac{(xy^\prime)^\prime}{x} \right]^\prime \...
W. Robin's user avatar
  • 491
0 votes
2 answers
5k views

How to solve the second order differential equation [duplicate]

I've been trying to do code this for a two or so hours, and I can't seem to do it. Please help.. I am trying to solve the following second-order differential equation: ...
John's user avatar
  • 3
2 votes
2 answers
695 views

DSolve not satisfying initial conditions

I am trying to solve the following nonlinear, non-homogeneous, first order ODE: $y'(t)=\sqrt{y(t)}-B$ $y(0)=B^2$ $B=const$ In code: ...
user64860's user avatar
  • 121
1 vote
2 answers
1k views

Solving recursion relation from power series

I am interested in solving differential equations in the form of power series. Let's say we have following equation: $$f^{\prime \prime} (\rho) + \left( \frac{2 e^{-k \rho}}{\rho} - \varepsilon \...
user16320's user avatar
  • 2,396
7 votes
1 answer
691 views

Trouble with shooting method for a 4th-order stiff ODE

The ODE I need to solve is $$\left(y^3y^{\prime\prime\prime}\right)^\prime+\frac{5}{8}xy^\prime-\frac{1}{2}y+\frac{c}{y}=0$$ where $\prime$ denotes differentiation, $c$ is a constant and $0<c\le1$....
W. Robin's user avatar
  • 491
0 votes
0 answers
906 views

Solving PDEs using Taylor series

I'm thinking of solving a Partial differential algebraic equation using multidimensional polynomial (i.e. Taylor series). Consider the PDAE: $$\mathbf F \left( \mathbf x, \mathbf y, \frac{\partial ...
Foad's user avatar
  • 615
0 votes
2 answers
407 views

Getting the coefficients of a series that solves a differential equations

I have an example from Stewart's Calculus where the equation $y'' + y = 0$ is solved using power series. The equation ...
BenNevis's user avatar
0 votes
1 answer
239 views

Differentiation of infinite series does not seem to be useful

Trying series solution of differential equations, the routine is to define a function as a series, and differentiate it. ...
梁國淦's user avatar
  • 392

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