How Do You Solve an Euler-Cauchy Equation Like x^2y'' + xy' - y = 1/x?

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SUMMARY

The discussion focuses on solving the Euler-Cauchy equation represented by x²y'' + xy' - y = 1/x. The correct approach involves identifying the coefficients a and b, where a should be +1 instead of -1. After determining the roots using the characteristic equation m(m-1) + am + b = 0, users can apply the method of variation of parameters for the particular solution. Alternatively, the change of variable u = ln(x) can simplify the equation to a constant coefficients form.

PREREQUISITES
  • Understanding of Euler-Cauchy equations
  • Familiarity with characteristic equations
  • Knowledge of variation of parameters method
  • Basic concepts of differential equations
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  • Study the method of undetermined coefficients for particular solutions
  • Learn about the change of variables in differential equations
  • Explore advanced techniques for solving differential equations
  • Review the application of logarithmic transformations in differential equations
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Students studying differential equations, mathematicians solving advanced calculus problems, and educators teaching methods for solving Euler-Cauchy equations.

engineer_dave
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Homework Statement



Find the general solution of x^2y" + xy' - y = 1/x


Homework Equations



m(m-1) +am + b = 0 to solve an Euler Cauchy equation

The Attempt at a Solution



a=1 b=-1

m(m-1) -m -1 =0

m^2 - 2m -1 = 0

I just want to know whether the first step is right. And once I find out the values of M, do I use variation of parameters to find the particular solution? Thanks
 
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engineer_dave said:

Homework Statement



Find the general solution of x^2y" + xy' - y = 1/x


Homework Equations



m(m-1) +am + b = 0 to solve an Euler Cauchy equation

The Attempt at a Solution



a=1 b=-1

m(m-1) -m -1 =0

m^2 - 2m -1 = 0

I just want to know whether the first step is right. And once I find out the values of M, do I use variation of parameters to find the particular solution? Thanks
One obvious error: a= +1 here , not -1. Yes, you can use "variation of parameters". Also, because the right hand side is a power of x, you could use "undertermined coefficients" although it is slightly harder to "guess" the correct form for a particular solution in such an equation as compared to a "constant coefficients" equation. Finally, the change of variable u= ln(x) will convert this equation to a "constant coefficients" equation.
 

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