Laplace Transforms and third-order derivatives The question is to calculate the Laplace transform of $(1 + t.e^{-t})^3$. I know that this can be done using a property where the problem is of the form of $t.f(t)$. However, I seem to be messing up the third order derivative.  
This is a DIY exercise from the textbook and hence, no worked out solution.
I expanded the bracket $(1 + t^3e^{-3t} + 3te^{-t} + 3t^2.e^{-2t})$
and I mess up the third order derivative for $t^3.e^{-3t}$  
Can someone please how me how that is done ?

A property of the Laplace transform is that if the transform of $f(t)$ is $F(s)$, then the  transform of $f(t)e^{-ct}$ is $F(s+c)$. To see this property for your self find the transform for $f(t) = 1$, the constant function and then compare it with the transform of $e^{-ct}$.
