Inverse Laplace Transform: How to Manipulate Fractions for Completing the Square

TyErd
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Homework Statement


Find the inverse laplace transform of \frac{3s + 7}{s^{2} - 2s + 10}

Homework Equations


completing the square.
e^{at}sin(bt) = \frac{b}{(s-a)^{2} + b^{2}}
e^{at}cos(bt) = \frac{s-a}{(s-a)^{2} + b^{2}}

The Attempt at a Solution


F(s)= \frac{3s + 7}{s^{2} - 2s + 10}
F(s) = \frac{3s + 7}{(s-1)^{2} +9}
F(s) = \frac{3s}{(s-1)^{2} +9} + \frac{7}{(s-1)^{2} +9}

after this i don't know how to manipulate the first fraction to fit the cosine equation. I know the 3 can be taken up front and a=1 and b=3 I am pretty sure when comparing with the cosine equation but there the problem of making s into s-1.
 
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Don't you have the shifting theorems? Like$$
\mathcal L e^{at}f(t) = \mathcal L(f(t))|_{s \to s-a}$$
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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