Laplace Transformation, Translation Property

Therefore, the solution to the initial value problem is y(t) = 2t2e-t + te-t + 2e-t. In summary, the Laplace Translation Property states that the inverse Laplace transform of a function G(s-a) is equal to the original function F(t) multiplied by e^at. We can use this property to solve initial value problems in Laplace transforms.
  • #1
ultimatejulia
1
0
Can anyone do a very comprehensive breakdown of the Laplace translation property for me? I don't understand how to apply it:
L[eat f(t)] = L[f(t)] s-> s-a

Here is a specific problem that applies it:

Homework Statement



Y(s) = 4/(s+1)3 + 1/(s+1)2 + 2/(s+1)

I need to perform an inverse Laplace transform to find the solution to this initial value problem (beginning parts of the problem omitted).

Homework Equations



L[eat f(t)] = L[f(t)] s-> s-a

The Attempt at a Solution



let E = (s+1);
L-1 (4/E3 + 1/E2 + 2/E) = 2t + t + 2

y(t) = 2t2e-t + te-t + 2e-t

... but why?
 
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  • #2
The Laplace Translation Property states that if we have a function F(s) and want to transform it to a new function G(s-a), then the inverse Laplace transform of G(s-a) is equal to the original function F(t) multiplied by e^at. In our problem, we have Y(s) = 4/(s+1)3 + 1/(s+1)2 + 2/(s+1). We can rewrite this as Y(s) = 4E3 + E2 + 2E, where E = (s+1). We can now apply the Laplace translation property to obtain:L-1(4E3 + E2 + 2E) = L-1(4E3) + L-1(E2) + L-1(2E) = 4e-t + te-t + 2e-t = 2t2e-t + te-t + 2e-t
 

Related to Laplace Transformation, Translation Property

1. What is the Laplace transformation?

The Laplace transformation is a mathematical operation that converts a function of time into a function of complex frequency. It is often used in engineering and physics to solve differential equations and analyze systems in the frequency domain.

2. What is the translation property of the Laplace transformation?

The translation property of the Laplace transformation states that if a function f(t) is transformed into F(s), then a shifted version of f(t) by a constant a will be transformed into e^(-as)F(s). In other words, a translation in the time domain corresponds to a multiplication by an exponential in the frequency domain.

3. How is the translation property used in solving differential equations?

The translation property is useful in solving differential equations because it allows us to transform a differential equation with initial conditions into an algebraic equation in the frequency domain. This makes it easier to solve for the unknown function and obtain its inverse Laplace transform to get the solution in the time domain.

4. Can the translation property be applied to functions with more than one variable?

No, the translation property only applies to functions of one variable. It cannot be extended to functions with multiple variables because the exponential factor e^(-as) would become a multivariable function, which is not allowed in the Laplace transformation.

5. Are there any limitations to the translation property?

One limitation of the translation property is that it only works for functions that are absolutely integrable. This means that the integral of the function must converge for all values of s. Additionally, the translation property may not be applicable if the function has a singularity at the point of translation, as it may result in an undefined or infinite value in the frequency domain.

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