Problem with finding second solution to ODE

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In summary, the problem is to find the series solution to a given differential equation and the ansatz method was used to find the solutions to the indicial equation. The first solution was obtained, but there is difficulty obtaining the second solution using the recurrence relation. This is because when the roots of the indicial equation differ by an integer, the second root may not yield a solution. The textbook and Wikipedia page provide methods for obtaining a second solution in such cases.
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Judas503
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1. The problem is to find the series solution to the following differential equation
$$ x^2 \frac{d^2 x}{dx^2}+x\frac{dy}{dx}+(x^2 - 1)y $$








3. Using the ansatz $$ y = \sum _{\lambda = 0}^{\infty}a_{\lambda}x^{k+\lambda}$$ the
solution to the indicial equation was found to be k=1 and k=-1. I obtained a solution for k = 1, however I am having a problem with obtaining the second solution. The recurrence relation for k = -1 is $$ a_{j}=-\frac{a_{j-1}}{(j-1)(j-2)+j-2} $$ which diverges for j = 2. In this case, is it possible to obtain a solution for k = -1?
 
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If the roots of the indicial equation differ by an integer, the second root may not yield a solution, which appears to be the case here. Your textbook probably covers how to get a second solution in such a case, and it's mentioned on this Wikipedia page: http://en.wikipedia.org/wiki/Frobenius_method#Double_roots
 
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1. What is the problem with finding a second solution to an ODE?

The problem with finding a second solution to an ODE is that it is not always possible. In some cases, an ODE may only have one unique solution.

2. Why is it important to find a second solution to an ODE?

Finding a second solution to an ODE is important because it allows for a more thorough understanding of the behavior of the system described by the ODE. It can also provide additional insights and alternative approaches for solving the problem.

3. What are some techniques for finding a second solution to an ODE?

Some techniques for finding a second solution to an ODE include using the method of variation of parameters, applying the reduction of order technique, and using the method of undetermined coefficients.

4. Can a second solution to an ODE be found numerically?

Yes, a second solution to an ODE can be found numerically using computational methods such as Euler's method or the Runge-Kutta method. However, these numerical solutions may not always be as accurate as analytical solutions.

5. Are there any restrictions on the domain of a second solution to an ODE?

Yes, there are restrictions on the domain of a second solution to an ODE. The domain must be consistent with the initial conditions and any boundary conditions given for the ODE. It must also satisfy any constraints imposed by the problem being modeled by the ODE.

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