Differential equation with Laplace transform

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SUMMARY

The discussion focuses on solving the differential equation \( t y'' + (3t-1) y' + 3y = 6 e^{-3t} \) using the Laplace transform. The user attempted to apply the Laplace transform but encountered difficulties, particularly with the terms \( L[t y''] \) and \( L[t y'] \). The correct application of the Laplace transform involves recognizing the negative sign in the derivatives, leading to the equation \( (s^2 + 3s)Y' + (s + 6)Y = \frac{6}{s+3} \). The user is advised to carefully check the application of the transform to avoid errors in the solution.

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Homework Statement


t y'' + (3 t-1) y' + 3 y = 6 e^{-3t}
y(0) = 1
y(5) = 2

Homework Equations



The Attempt at a Solution


I tried applying the Laplace transform to the equation but I was having a little trouble...
L [t·y''] = -dL[y'']/ds = s2·Y' + 2·s·Y - y(0) = s2·Y' + 2·s·Y - 1
L [t·y'] = -dL[y']/ds = s·Y' + Y
Therefore:
s^2 Y' + 2 s Y - 1 + 3 s Y' +3 Y - s Y + 1+ 3 Y = \frac{6}{s+3}
(s^2+3s)Y'+(s+6)Y=\frac{6}{s+3}

And then solve the Y(s) and then use the inverse transform.
But it doesn't yield the correct result. I did the rest on the computer so I guess it's when I apply the transform where I make a mistake.

Thanks for your help.
 
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I think you dropped the negative sign when calculating L[t y''] and L[t y'].
 

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