Ned help with Laplace transform not sure what to do but have a idea

the question is find the Laplace transform of;

$\displaystyle te^{\text{-t}}cos(3t$) i think u gotta apply the therom $\displaystyle (-1)^nd^n/ds^n[F(s)]$

meaning it wil be the dervitive of the transform $\displaystyle e^{\text{-t}}cos(3t$) am i close :P lol