Linear Differential Equation to solve?

abrowaqas
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Homework Statement



this is Cauchy's LDE.. someone help me to solve this equation.

x^2 y'' + 3x y' + y = 1/(1-x)^2

Homework Equations


The Attempt at a Solution



i started it with substituting
x= e^t
then ln x = t
and d/dt = D

hence the equation becomes

{ D(D-1) +3D +1} y = 1/(1+e^t)^2

and i got characteristics equation
as
Yc=(c1 + c2x ) e^-1

now i have problem in findind Particular Intergral i-e Yp..

i-e
Yp = 1 / {(D+1)^2 (1+e^t)^2 } ?

somebody help to complete its solution?
 
Last edited:
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I've only seen that sort of equation referred to as an Euler's differential equation. See, e.g., http://mathworld.wolfram.com/EulerDifferentialEquation.html.

You solve the homogeneous equation by substituting y = x^n and finding appropriate values for n. (In your case, you run into a double root, so you'll have to use reduction of order to find the second solution.) Then you can use variation of parameters to find the solution to the nonhomogeneous equation.
 
thanks Obafgkmrns... i got it..
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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