Inverse laplace transofrm of natural logarithm

exidez
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Homework Statement



the inverse laplace transform of ln\frac{s+2}{s-5} using the inverse Laplace transform of the derivative

Homework Equations

L^{-1}{\frac{d^{n}}{ds^{n}}F(S)} = (-1)^{n}t^{n}f(t)

The Attempt at a Solution



the integral of ln\frac{s+2}{s-5} I worked to be (s+2)ln(s+2)-(s+2) -(s-5)ln(s-5)+(s-5). So if this is F(S) then i still have no idea how to inverse it using the inverse Laplace transform of the derivative

somehow i think I am going down the wrong road... ?
 
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ok, i think i got it!

i go the other way and make n = -1

I have never seen this but just to clear this up: if \frac{d}{ds}}F(S) is the derivative of F(S) then \frac{d^{-1}}{ds^{-1}}F(S) is the same as the integration of F(S) right?
 
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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