Find the Inverse Laplace of 1/(s^3)

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SUMMARY

The inverse Laplace transform of 1/(s^3) is definitively t^2/2. This conclusion is derived from the Laplace transform table, which states that the transform of t^n, where n is a positive integer, is n!/s^(n+1). For n=2, this results in (2!/s^(2+1)), leading to the inverse transform being (1/2)t^2. The discussion emphasizes the importance of correctly interpreting the Laplace transform table to avoid confusion between the transform and its inverse.

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Find the Inverse Laplace of 1/(s^3)

is there some special rule for cube?

The answer is t^2/2

Looking at the Laplace Table t^n looks similar but its not it exactly. What should I do?
 
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tsslaporte said:
Find the Laplace of 1/(s^3)

You mean find the inverse transform.

is there some special rule for cube?

The answer is t^2/2

Looking at the Laplace Table t^n looks similar but its not it exactly.


What should I do?

So what does the table give you for ##t^n##? Can you modify it?
 
LCKurtz said:
You mean find the inverse transform.
So what does the table give you for ##t^n##? Can you modify it?

Yep Inverse sorry, ##t^n## , n = 1,2,3,... is (n!)/(s^n+1)

2/s^2 +1 ?
 
Are you asking for the "Laplace transform" or the "Inverse Laplace transform"? The standard notation uses "t" for the function and "s" for its Laplace transform.

A table of Laplace transforms, such as the one at http://tutorial.math.lamar.edu/pdf/Laplace_Table.pdf, will tell you that the Laplace transform of t^n, for n a positive integer, is n!/s^{n+1}.

So the inverse Laplace transform of 1/s^3= (1/2)(2/s^3)=(1/2)(2!/s^(2+1) is (1/2)t^2.

I just saw your response. I think you are misreading the table. It is not "s^n+ 1", it is s^{n+ 1}.
 
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HallsofIvy said:
Are you asking for the "Laplace transform" or the "Inverse Laplace transform"? The standard notation uses "t" for the function and "s" for its Laplace transform.

A table of Laplace transforms, such as the one at http://tutorial.math.lamar.edu/pdf/Laplace_Table.pdf, will tell you that the Laplace transform of t^n, for n a positive integer, is n!/s^{n+1}.

So the inverse Laplace transform of 1/s^3= (1/2)(2/s^3)=(1/2)(2!/s^(2+1) is (1/2)t^2.

Halls, don't you think we should have let him figure out that step?
 
Thanks,

where did the 1/2 come from?
 
If you cannot see that then you should not be taking this course. Look at your table of Laplace transforms again.
 

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