Frustrated with Inverse Laplace Transform: Help Needed!

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SUMMARY

The discussion focuses on the process of performing an inverse Laplace transform, specifically transitioning from the expression \(\frac{ \frac{-U}{s}}{R+sL+ \frac{1}{sC}}\) to the result \(- \frac{2 \sqrt{10}}{ \sqrt{15}}e^{-125t}sin(125 \sqrt{15})\). Key values include \(U= \sqrt{10}\), \(R=1\), \(L=4 \times 10^{-3}\), and \(C=1 \times 10^{-3}\). The user initially misapplied the formula but corrected it by realizing the need to adjust the numerator to \(\frac{-U/LC}{s^2+s(R/L)+(1/LC)}\), leading to the correct transformation.

PREREQUISITES
  • Understanding of inverse Laplace transforms
  • Familiarity with differential equations
  • Knowledge of circuit analysis concepts, specifically RLC circuits
  • Proficiency in algebraic manipulation of complex fractions
NEXT STEPS
  • Study the properties of inverse Laplace transforms
  • Learn about the application of Laplace transforms in circuit analysis
  • Explore the derivation of standard Laplace transform pairs
  • Practice solving differential equations using Laplace transforms
USEFUL FOR

Students preparing for mid-terms in engineering or mathematics, particularly those focusing on control systems, circuit analysis, or differential equations involving Laplace transforms.

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Homework Statement



This isn't a homework, I'm just trying to recap for a mid-term. Anyways, it's about inverse Laplace transformation and this crap is starting to piss me off! How the heck are you supposed to go from [tex]\frac{ \frac{-U}{s}}{R+sL+ \frac{1}{sC}}[/tex] to [tex]- \frac{2 \sqrt{10}}{ \sqrt{15}}e^{-125t}sin(125 \sqrt{15})[/tex]?

Homework Equations



The values are: [tex]U= \sqrt{10}, R=1, L=4*10^{-3}, C=1*10^{-3}[/tex]

The Attempt at a Solution



My best attempt so far has gotten me to [tex]\frac{-U}{s^2+s(R/L)+(1/LC)}=\frac{- \sqrt{10}}{125 \sqrt{15}} \frac{125 \sqrt{15}}{(s+125)^2+(125 \sqrt{15})^2}[/tex]. I know this is pretty close but not close enough...
 
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I found it out myself. Instead of [tex]\frac{-U}{s^2+s(R/L)+(1/LC)}[/tex] I should have had [tex]\frac{-U/LC}{s^2+s(R/L)+(1/LC)}[/tex]. This gives me the right answer.
 

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