Hi..i need to determine the inverse laplace of F(s)=((s^2)-(∏^2))/((s^2)+(∏^2))^2..........by either differentiation or integration of Transforms method..no other methods..i know thee inverse laplace of this s-domain function is t cos(∏t) but i cant figure out a way to show this through either of the two methods mentioned.plz help thanks