Frobenius method solution for linear ODE

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The discussion centers on solving the second-order linear ordinary differential equation (ODE) x^2 u'' - x(x u' - u) = 0, which requires a logarithmic term in the general solution. A participant confirms that the first solution, y = x, is correct, but indicates that the second solution provided is incorrect. They reference external resources for solving both homogeneous and inhomogeneous versions of the ODE, emphasizing the importance of including a fundamental solution involving integrals. The key takeaway is that the complete solution should incorporate logarithmic terms and specific integrals for accuracy. The conversation highlights the complexity of solving ODEs with variable coefficients.
zokomoko
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I've been given the ODE:
x^2 u''-x (x u'-u)=0
Solve.

It's suppose to be an example in which a logarithmic term is required for the general solution.
I would be glad if someone could look at what I've done and see if my solution is correct / incorrect.

Thank you in advance for your time and effort :wink:



p.s: I've attached a zip file which contains a WMF type file of the problem, if anyone has mathtype it's easier to read than the attached GIF image.
 

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Your 1st solution of y = x is correct, but the other solution is wrong.

Please refer to the below question in http://www.voofie.com" .

http://www.voofie.com/content/86/how-to-solve-this-2nd-order-linear-differential-equation/"

The question solves an inhomogeneous version of your question using http://www.voofie.com/content/84/solving-linear-non-homogeneous-ordinary-differential-equation-with-variable-coefficients-with-operat/" .

If there is an inhomogeneous function of f(x), the solution should be:
\Rightarrow y=C_1x\int e^xx^{-2} dx+ C_2 x+x\int \left(e^xx^{-2} \int e^{-x} x f(x)dx\right) \, dx

And you can see, the fundamental solution that you are missing is:
x\int e^xx^{-2} dx
 
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