1. The problem statement, all variables and given/known data How can I annihilate the following ? 4e-2t*cos(2t) 2. Relevant equations 3. The attempt at a solution I know that if I want to annihilate e-t it would be (D-1) and to annihilate cos(2t) it would be (D2+22) but what happens if they are multiplied ? how do I annihilate this ? I tried something and I'm not sure it's correct but I got (D2+4)/(D-2) ?