Help with differential equation

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SUMMARY

The discussion focuses on solving a differential equation using the convolution integral and inverse Laplace transforms. The equation presented involves terms such as X(s) and F(s), where X(s) is expressed as a sum of fractions involving s and constants c1, c2, and k. The participants confirm that c3 should equal k and emphasize the application of the convolution rule for the first inverse Laplace transform. The conversation concludes with an acknowledgment of the helpfulness of the provided insights.

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Fiorella
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Solve with convolution integral:

Click http://i3.photobucket.com/albums/y62/Phio/eq.jpg" to see the equation.

So far what I've got is http://i3.photobucket.com/albums/y62/Phio/attempt.jpg" . I don't know what else to do from there, or if what I'm doing is right...


Any help appreciated!
 
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First, c_3 should be equal to k from your DE should it not?

Second,

X(s)=\frac{F(s)}{s^2+k}+\frac{c_1s}{s^2+k}+\frac{c_2}{s^2+k}\implies x(t)=\mathcal{L}^{-1} \left\{ \frac{F(s)}{s^2+k}+\frac{c_1s}{s^2+k}+\frac{c_2}{s^2+k} \right\}
=\mathcal{L}^{-1} \left\{ \frac{F(s)}{s^2+k} \right\}+\mathcal{L}^{-1} \left\{ \frac{c_1s}{s^2+k} \right\}+\mathcal{L}^{-1} \left\{ \frac{c_2}{s^2+k} \right\}

You shouldn't have much trouble doing the last two inverse Laplace transforms, and the first one can be done using the convolution rule...
 
gabbagabbahey said:
First, c_3 should be equal to k from your DE should it not?

Second,

X(s)=\frac{F(s)}{s^2+k}+\frac{c_1s}{s^2+k}+\frac{c_2}{s^2+k}\implies x(t)=\mathcal{L}^{-1} \left\{ \frac{F(s)}{s^2+k}+\frac{c_1s}{s^2+k}+\frac{c_2}{s^2+k} \right\}
=\mathcal{L}^{-1} \left\{ \frac{F(s)}{s^2+k} \right\}+\mathcal{L}^{-1} \left\{ \frac{c_1s}{s^2+k} \right\}+\mathcal{L}^{-1} \left\{ \frac{c_2}{s^2+k} \right\}

You shouldn't have much trouble doing the last two inverse Laplace transforms, and the first one can be done using the convolution rule...

Oooh I thought about that...this helps!

Thanks a lot!
 

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