Differential equations - 2nd order homogenous eq'n w/ unknown

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Homework Help Overview

The discussion revolves around solving a second-order homogeneous differential equation of the form t d²y/dt² - (1+3t) dy/dt + 3y = 0, with a proposed solution structure involving an exponential function. Participants explore the general solution and the implications of manipulating constants in the solution.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the form of the solution and the validity of steps taken in deriving the general solution. Questions arise regarding the method of reduction of order and the reasoning behind dividing by t.

Discussion Status

The discussion includes attempts to confirm the correctness of a manipulation involving constants in the solution. Some participants express uncertainty about the steps taken, while others provide affirmation of the approach. There is an ongoing exploration of the method and its implications.

Contextual Notes

One participant notes that they are unfamiliar with the problem type, indicating a potential gap in foundational knowledge. The discussion also reflects on the appropriateness of certain algebraic manipulations within the context of the problem.

braindead101
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Given that the equation
t d^2y/dt^2 - (1+3t) dy/dt + 3y = 0. has a solution of the form e^ct, for some constant c, find the general solution (The answer is y(t) = c1(1+3t) + c2e^(3t)

Edit: I finished this question as i figured it out. but when i come down to the last step, i get this
y1(t) = e^3t
y2(t) = -1/3t - 1/9

y(t) = c1y1(t) + c2y2(t)
y(t) = c1e^3t + c2(-1/3t-1/9)
y(t) = c1e^3t + -1/9c2(3t+1)

can i bet c3 = -1/9c2?
so it's
y(t) = c1e^3t + c3(3t+1)
 
Last edited:
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braindead101 said:
I havn't done a question like this, so I don't know where to start. should i divide everything by t and do reduction of order?

Why divide by t?

Are you familiar with how the reduction of order method woks? This site should help
http://tutorial.math.lamar.edu/AllBrowsers/3401/ReductionofOrder.asp
 
Last edited by a moderator:
sorry i figured out how to do it,
can u confirm whether i am allowed to do the last step? i don't see why not but just incase
 
braindead101 said:
can u confirm whether i am allowed to do the last step? i don't see why not but just incase

Yes, it's right.
 

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