Can This Integral Be Solved Using an Integrating Factor?

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Discussion Overview

The discussion revolves around the attempt to solve the differential equation given by (2x²y - e^(-x²))dx + (x + 1)dy = 0. Participants explore various methods, including the use of integrating factors and the classification of the equation as linear.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant attempts to find an integrating factor and derives P = e^(x² - 2x + ln|x|), but expresses uncertainty about the next steps after simplification.
  • Another participant suggests an integrating factor of μ = e^(x² - 2x + ln(1 + x)) and recommends multiplying the equation by this factor to solve it as an exact equation.
  • A different participant reclassifies the equation as a linear ordinary differential equation (ODE) and proposes using classical methods for solving linear ODEs.
  • One participant repeats their earlier post, indicating they are still seeking assistance with the problem.
  • A link to Wolfram Alpha is provided by another participant, presumably to illustrate or check the solution to the ODE.

Areas of Agreement / Disagreement

Participants present multiple approaches to the problem, including the use of integrating factors and the classification of the equation as linear. There is no consensus on the best method or the next steps to take, indicating ongoing disagreement and exploration.

Contextual Notes

Some participants' approaches depend on specific assumptions about the integrating factors and the methods for solving ODEs, which may not be universally agreed upon. The discussion reflects various interpretations and techniques without resolving the mathematical steps involved.

busyocean
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I've tried almost everything but i still get stuck when finding the integral of :

(2x^2y-e^(-x^2))dx+(x+1)dy =0

To attempt to solve it i did the following:----> since the DE is not exact :

1) [M(x,y)/dy - N(x,y)/dx]/N(x,y) = [2x^2-1/x+1]
2) ∫[2x^2-1/x+1] =
3) Integrating Factor: e^(x^2 - 2x +ln|x|) to make it smaller I'm going to call

{e^(x^2 - 2x +ln|x|)} = P

4) P*[(2x^2-e^-(x^2))dx + (x+1)dy] =0

After simplifying I get: [(2x^2)ye^(x^2)-1]dx = [e^(x^2)](x+1)dy

After that I don't know what to do.
 
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I get the integrating factor:

[tex]\mu=e^{x^2-2x+\ln(1+x)}[/tex]

Once you get the integrating factor, multiply both sides of equation by it, then use the techniques of solving an exact equation (taking those partial integrals and all).
 
Hi !
(2x²y-e^(-x²))dx+(x+1)dy = 0
is a linear ODE :
(x+1)y' +(2x²)y = e^(-x²)
You may solve it in using the classical method to solve linear ODEs.
 
busyocean said:
I've tried almost everything but i still get stuck when finding the integral of :

(2x^2y-e^(-x^2))dx+(x+1)dy =0

To attempt to solve it i did the following:----> since the DE is not exact :

1) [M(x,y)/dy - N(x,y)/dx]/N(x,y) = [2x^2-1/x+1]
2) ∫[2x^2-1/x+1] =
3) Integrating Factor: e^(x^2 - 2x +ln|x|) to make it smaller I'm going to call

{e^(x^2 - 2x +ln|x|)} = P

4) P*[(2x^2-e^-(x^2))dx + (x+1)dy] =0

After simplifying I get: [(2x^2)ye^(x^2)-1]dx = [e^(x^2)](x+1)dy

After that I don't know what to do.

Here is a cool LaTeX guide: https://www.physicsforums.com/showpost.php?p=3977517&postcount=3
 

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