Impulse response function & Laplace transforms

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The discussion focuses on finding the output of a system given its Laplace transform of the impulse response function, H(s) = 1/(s² + s + 1), and the input x(t) = sin²(t-1)U(t-1). The user has derived the Laplace transform of the input, X(s), but is uncertain about its correctness and the subsequent steps. They have calculated Y(s) using the relationship Y(s) = H(s)X(s) but are seeking alternative methods, such as the convolution integral, to simplify the process. Suggestions include using partial fractions to separate terms in Y(s) for easier inverse transformation and considering the convolution of the input and impulse response functions. The conversation highlights the complexities of the problem and the various approaches to solving it.
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i am given the Laplace transform of an impulse response function, as well as its input. i am supposed to find its output.

H(s) = 1/s2 + s + 1
x(t) = sin2(t-1)U(t-1)

what i have done so far is the following:
i know that Y(s) = H(s)X(s) and from this i can easily find y(t)
so i found X(s) since H(s) is already given...this may be wrong
X(s) = 2e-s/s2 + 4

then i found Y(s)
Y(s) = 2e-s/(s2 + s + 1)(s2 + 4)
then i know that y(t) should be 2y(t-1) because of the e-s time shifting

but i am stuck here... is there a better way to solve this problem using Convolution integral or any other way? i know how to do both the partial fractions method and convolution integral but i keep getting stuck. i think i have set up the problem wrong, perhaps in the X(s) solution
 
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Yes it will be messy all ways!
 
If you want to continue with what you started, ignore the exponential factor for now and find the inverse Laplace transform of

\frac{2}{(s^2+s+1)(s^2+4)}

Start by using partial fractions to get separate terms:

\frac{2}{(s^2+s+1)(s^2+4)} = \frac{As+B}{s^2+s+1}+\frac{Cs+D}{s^2+4}


The more painful way of finding y(t) would be to find h(t) from H(s) and then convolve x(t) and h(t).
 

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