How would I take the laplace transform of f(t)= te^tsin^2(t)?

In summary, the conversation discusses the Laplace transform of the function f(t)= te^tsin^2(t). The use of integration by parts and the half-angle formula is suggested to compute the transform directly.
  • #1
Jim wah
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How would I take the laplace transform of f(t)= te^tsin^2(t)?
 
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  • #2
You mean t et sin(2t)? What's causing you the problem? It is pretty straight-forward application of the definition case.
 
  • #3
DevacDave said:
You mean t et sin(2t)? What's causing you the problem? It is pretty straight-forward application of the definition case.
No the equation is f(t)= te^tsin^2(t)
 
  • #4
Still, it's a standard case (I have a vague recall of this exact function class being important in telecommunication). Perfectly doable via integration by parts. Is this where you got stuck?
 
  • #5
DevacDave said:
Still, it's a standard case (I have a vague recall of this exact function class being important in telecommunication). Perfectly doable via integration by parts. Is this where you got stuck?
Kinda, Is there anyway to figure out the transform of sin^2(t) then use the theorem for the e^t and t?
 
  • #6
I don't know of having seen that in a table anywhere, it doesn't look like an elementary form, so what you need to do is compute the transform directly using the Laplace transformation definition.
Jim wah said:
Kinda, Is there anyway to figure out the transform of sin^2(t) then use the theorem for the e^t and t?

For integrating the sin2(t) in the transformation integral you need to use the half-angle formula: http://www.sosmath.com/trig/douangl/douangl.html
 
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Likes Jim wah
  • #7
jack476 said:
I don't know of having seen that in a table anywhere, it doesn't look like an elementary form, so what you need to do is compute the transform directly using the Laplace transformation definition.For integrating the sin2(t) in the transformation integral you need to use the half-angle formula: http://www.sosmath.com/trig/douangl/douangl.html
Thank you so much!
 

Related to How would I take the laplace transform of f(t)= te^tsin^2(t)?

1. How do I take the Laplace transform of f(t)=te^tsin^2(t)?

The Laplace transform of a function f(t) is defined as F(s) = ∫e^(-st)f(t)dt. So, for f(t)=te^tsin^2(t), we have F(s)=∫te^(-st)sin^2(t)dt. From the Laplace transform table, we know that the transform of sin^2(t) is 1/(s^2+4). Therefore, F(s)=∫te^(-st)/(s^2+4)dt. Using integration by parts, we can evaluate this integral to get F(s)=(-1/2)e^(-st)/(s^2+4)+sF(s). Solving for F(s), we get F(s)=(-1/2)e^(-st)/(s^2+4(s+1)).

2. Can I use a calculator to take the Laplace transform of f(t)=te^tsin^2(t)?

Yes, there are many online calculators and software programs available that can quickly and accurately compute Laplace transforms. However, it is always helpful to understand the steps and concepts behind the calculation before relying on a calculator.

3. What is the purpose of taking the Laplace transform of a function?

The Laplace transform is a mathematical tool used to simplify differential equations and make them easier to solve. It converts a function of time, f(t), into a function of a complex variable, F(s), making it easier to manipulate and solve. It is commonly used in fields such as engineering, physics, and mathematics.

4. Is there a specific range of values for which the Laplace transform is valid?

Yes, the Laplace transform is only valid for functions that are defined for t≥0 and have a finite number of discontinuities, also known as piecewise continuous functions. It is also valid for functions that grow at most polynomially as t→∞.

5. Are there any other methods for taking the Laplace transform?

Yes, there are other methods such as using the Laplace transform table, partial fraction decomposition, and convolution. These methods may be more efficient for certain types of functions, but the basic definition of the Laplace transform remains the same.

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