Homogeneous differential equation

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Homework Help Overview

The problem involves solving a homogeneous differential equation of the form (1-xcotx)y''-xy'+y=0, where one solution, y1(x)=x, is provided. The goal is to find a second solution, y2(x), ensuring that y1 and y2 are linearly independent.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the method of finding a second solution using the form y2(x)=u(x)y1(x) and explore the implications of this substitution. There are questions about the complexity of the resulting equations and whether to continue with the approach.

Discussion Status

The discussion is ongoing, with some participants providing guidance on the substitution method and others expressing uncertainty about the complexity of the resulting equations. There is a mix of exploration and verification of steps taken in the process.

Contextual Notes

One participant notes a limitation in their ability to use certain substitution methods, which may affect their approach to finding the second solution.

annoymage
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Homework Statement



(1-xcotx)y''-xy'+y=0

y1(x)=x is a solution

find the second solution, y2(x), y1 and y2 are linear independent

Homework Equations



N/A

The Attempt at a Solution



i only know how to find it by auxiliary equation by substitute y=erx
and also i can't use substitution y=xr

how to do this?
 
Last edited:
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With these types of problems, where you are given one solution you usually look for a second solution of the form [itex]y_2(x)=u(x)y_1(x)[/itex]. So, try that substitution and see what you get.
 
gabbagabbahey said:
With these types of problems, where you are given one solution you usually look for a second solution of the form [itex]y_2(x)=u(x)y_1(x)[/itex]. So, try that substitution and see what you get.

y=ux

y'=u'x+u

y''=u''x+2u

substitute and get

-(x2u''+2xu)cot(x)-x2u'+xu''+2u=0

like this right?

but it seems to become more complicated is it? or should i continue?
 
annoymage said:
y''=u''x+2u

You'll want to double check this :wink:
 
owho, yes yes, i get the answer. thank you very much.. ^^v
 

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