Convolution Laplace Transform

[netapparition]

Can anyone get me started with the following transforms using convolution theory?

L^-1 {1 / (s^2+k^2)^2}

and

L^-1 {8 / (s^2+1)^3}

Any help would be greatly appreciated

CA

Casanovamp@yahoo.com

[ReyChiquito]

if \tilde{f} denotes the Laplace transform

\widetilde{f * g}(s)=\tilde{f}(s)\tilde{g}(s)

use this with known inverse Laplace transforms.

You can check your results using partial fractions also.