Laplace of a Unit Step Function

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SUMMARY

The discussion focuses on finding the Laplace transform of the unit step function defined as f(t) = {0, if t<4 and (t-3)^3 if t≥4. The user attempts to express the function using the unit step function u(t-4) and seeks clarification on whether to use u(t-4)(t-4)^3 or u(t-4)^4. The correct approach involves changing the variable of integration to u=t-4 and applying the Laplace transform definition accordingly. The user initially proposes an incorrect answer for the Laplace transform, indicating a need for further guidance on the integration process.

PREREQUISITES
  • Understanding of Laplace transforms and their properties
  • Familiarity with unit step functions, specifically u(t-a)
  • Knowledge of polynomial functions and their manipulation
  • Basic calculus skills, particularly integration techniques
NEXT STEPS
  • Study the definition and properties of the Laplace transform
  • Learn how to manipulate unit step functions in Laplace transforms
  • Practice solving Laplace transforms of piecewise functions
  • Explore integration techniques relevant to Laplace transforms
USEFUL FOR

Students studying differential equations, engineers applying Laplace transforms in control systems, and anyone needing to understand the transformation of piecewise functions.

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Homework Statement


f(t) = {0, if t<4 and (t-3)^3 if t\geq4


The Attempt at a Solution


I feel like its pretty basic but i can't get it down
I have u(t-4)(t-4)^3

Can i change it to u(t-4)^4?
Then do i multiply it out and take the laplace?
If someone can work it out for me that would be awesome, I have about 20 more and I just need an example, i appologize if that's against the rules.

I want to say the answer is (6/s^4 - 24/s^3 + 48/s^2 - 64/s)e^-4s but that's wrong.
 
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I don't know if this is the 'laplace' way of doing things, but change the variable of integration to u=t-4. Then what does the integral that defines the laplace transform look like in terms of u?
 

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