Laplace transform of (e^-s) / [ (s)(s-3) ]

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SUMMARY

The discussion centers on finding the Laplace transform of the function (e^-s) / [(s)(s-3)]. The user correctly identifies the use of the formula L { f(t-a) H(t-a) } = (e^-(as)) F(s), determining that a = 1 and F(s) = 1 / [(s)(s-3)]. However, a critical point raised is the potential confusion between finding the Laplace transform and the inverse Laplace transform, which are fundamentally different operations. The author’s solution lacks the Heaviside function H(t-a), leading to questions about its correctness.

PREREQUISITES
  • Understanding of Laplace transforms and their properties
  • Familiarity with the Heaviside step function H(t-a)
  • Knowledge of the formula L { f(t-a) H(t-a) } = (e^-(as)) F(s)
  • Basic algebraic manipulation of rational functions
NEXT STEPS
  • Study the differences between Laplace transforms and inverse Laplace transforms
  • Learn about the Heaviside step function and its applications in Laplace transforms
  • Explore examples of Laplace transforms involving exponential functions
  • Review the properties of Laplace transforms for piecewise functions
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Students and professionals in engineering, mathematics, and physics who are working with Laplace transforms, particularly those seeking to clarify the application of the Heaviside function in transform problems.

foo9008
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Homework Statement



find the laplace transform of (e^-s) / [ (s)(s-3) ]

since there's (e^-s) which can be found in L { f(t-a) H(t-a) } = (e^-(as)) F(s) , so , i found a = 1 , then i found F(s) = 1/ [ (s)(s-3) ] , formula :
HGbjXV9.jpg


i have attached the working below , is it correct ? btw , the author's ans doesn't have H(t-a) , is the author's ans wrong ?
author's ans :

2v2kPyD.jpg


Homework Equations

The Attempt at a Solution


my working :
AD0HQrk.png


which is correct ? the author ? or me ?
 
Last edited:
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foo9008 said:

Homework Statement



find the laplace transform of (e^-s) / [ (s)(s-3) ]

since there's (e^-s) which can be found in L { f(t-a) H(t-a) } = (e^-(as)) F(s) , so , i found a = 1 , then i found F(s) = 1/ [ (s)(s-3) ] , formula :
HGbjXV9.jpg


i have attached the working below , is it correct ? btw , the author's ans doesn't have H(t-a) , is the author's ans wrong ?
author's ans :

2v2kPyD.jpg


Homework Equations

The Attempt at a Solution


my working :
AD0HQrk.png


which is correct ? the author ? or me ?

There is no way that an author would have asked you to find the Laplace transform of ##e^{-s}/(s(s-3))##. Are you sure it does not ask for the INVERSE Laplace transform? There is a huge difference between these two concepts.
 

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