Cauchy-Euler Differential Equation

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SUMMARY

The discussion focuses on solving the Cauchy-Euler differential equation given by x²y'' - 2xy' + 2y = x with boundary conditions y(1) = 0 and y(2) = 0. The equation is confirmed as a Cauchy-Euler equation, and the characteristic equation is derived as r(r-1) - 2r + 2 = 0, yielding roots r = 2 and r = 1. A particular integral is proposed using the form y = Ax ln(x), which successfully addresses the non-homogeneous part of the equation. The transformation x = e^t simplifies the equation to one with constant coefficients, facilitating the solution process.

PREREQUISITES
  • Cauchy-Euler differential equations
  • Characteristic equations and their solutions
  • Particular integrals in differential equations
  • Change of variables in differential equations
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  • Study the method of solving Cauchy-Euler equations in detail
  • Learn about finding particular integrals for non-homogeneous differential equations
  • Explore the transformation techniques for simplifying differential equations
  • Investigate the application of the method of undetermined coefficients
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Homework Statement


Consider the equation x2y''-2xy'+2y=x with bountary conditions y(1)=0, y(2)=0.

I don't know how to solve this without treating it as a Cauchy-Euler equation but I'm struggling because the equation equals x.


The Attempt at a Solution


By treating this as a Cauchy-Euler equation x2y''-2xy'+2y=0 and using y=xr, I get that r=2,1.
I can't find a particular integral for the equation though and I'm not even sure this is a Cauchy-Euler equation anymore.
 
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Yes that is a 'Cauchy-Euler' equation and, yes, its characteristic equation is r(r-1)- 2r+ 2=(r- 2)(r- 1)= 0 so that x and [itex]x^2[/itex] are solutions. Since "x" is already a solution, try y= Ax ln(x) as a solution to the entire equation.

That works (and Cauchy-Euler equations are especially easy) because the change of variable [itex]x= e^t[/itex] reduces that equation to the equation with constant coefficients [itex]y''- 3y'+ 2y= e^t[/itex] (the primes now indicate differentiation with respect to t).
 

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