How can I find the analytical solution for the system?

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Homework Help Overview

The discussion revolves around finding an analytical solution for a differential equation involving a nonlinear term and a sinusoidal function. The equation is presented in the context of a Bernoulli differential equation, with parameters defined as positive constants.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to solve the differential equation using Bernoulli equations but encounters difficulties in reaching a final result. Some participants ask for clarification on the substitution process to identify the specific challenges faced.

Discussion Status

Participants are actively discussing the steps taken by the original poster and exploring the nature of the integral involved in the solution. Guidance has been offered regarding expressing results in terms of unevaluated integrals, acknowledging that certain integrals do not have elementary solutions.

Contextual Notes

There is an acknowledgment of the complexity of the integral involved, with specific mention that integrals of the form presented do not yield elementary antiderivatives. This highlights potential constraints in finding a straightforward analytical solution.

Avan
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Homework Statement



dx(t)/dt = N0*sin(omega*t) * x(t) - ( N0*x^2 / k )

Omega,N0 and k are positive .

Homework Equations

The Attempt at a Solution


I tried to solve it using the Bernoulli equations but I could not get the last result.
 
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Show us what happens with the Bernoulli substitution so we can see what your difficulty is.
 
Here's the DE in a bit more readable form.
$$ \frac{dx}{dt} = N_0x(\sin(\omega t) - \frac{x}{k})$$
 
Last edited:
The result that I got is :

exp( (cos(omega*t) * (-N0/omega)) / x(t) = (N0 / k) * ( integral (exp( (cos(omega*t)) * (-N0/omega) ) ) ) dt

So I do not know how to find the integral when typically there is no specific solution for the integral of the Exponential function.
 
You may just have to express the result in terms of unevaluated integrals. Integrals of the form ##\int e^{\frac 1 \omega \cos(\omega t)}~dt## don't have elementary antiderivatives.
 

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