Inverse Laplace transform (Initial Value Problem)

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Homework Help Overview

The discussion revolves around finding the inverse Laplace transform of the function Y(s) = 1 / [ (s-1)^2 + 1 ]^2, which is related to solving a differential equation.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss attempts to use the translation theorem and sine formulas, as well as partial fraction decomposition. There are questions about how to proceed when faced with a squared denominator.

Discussion Status

The discussion includes various attempts to clarify the problem and explore different methods. Some participants express frustration over the lack of progress, while others suggest showing previous work to facilitate assistance. There is acknowledgment of a potential resolution through the application of Laplace transform tables.

Contextual Notes

Participants note the challenge of working with the squared denominator and the implications of the initial value problem context. There is a mention of homework constraints regarding the methods that can be used.

aero_zeppelin
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Homework Statement



I'm stuck trying to find out the inverse Laplace of F(s) to get y(t) (the solution for the differential equation):

Y(s) = 1 / [ (s-1)^2 + 1 ]^2



The Attempt at a Solution



I tried using a translation theorem and then apply the sine formula, but the denominator is still all squared. I also tried partial fractions to expand Y(s) but I didn't get it right...

Any suggestions please?
 
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aero_zeppelin said:

Homework Statement



I'm stuck trying to find out the inverse Laplace of F(s) to get y(t) (the solution for the differential equation):

Y(s) = 1 / [ (s-1)^2 + 1 ]^2



The Attempt at a Solution



I tried using a translation theorem and then apply the sine formula, but the denominator is still all squared. I also tried partial fractions to expand Y(s) but I didn't get it right...

Any suggestions please?

Yes: show us what you did and what you got. How can we possibly help if we have no idea of what your problem is?
 
[(s-1)+1]^2=[(s-1+i)(s-1-i)]^2

Therefore, \left[\frac{1}{ (s-1-i)(s-1+i) }\right]^2=\left[\frac{1}{2i}\left(\frac{1}{s-1-i}-\frac{1}{s-1+i} \right ) \right ]^2

Can you continue it from there?
 
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Ray Vickson said:
Yes: show us what you did and what you got. How can we possibly help if we have no idea of what your problem is?


My friend, that's the thing, I can't get past that. I stated the problem clearly: "I'm stuck trying to find out the INVERSE LAPLACE of the given Y(s) to get y(t)". There's no point in showing what I did before, it's not needed for what's after the equation I posted.

Anyway, I got it. It was just applying one of the formulas from the Laplace transform tables. I thought partial fractions or something else had to be done.

Thanks for your help
 

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