1. The problem statement, all variables and given/known data Find the laplace transform of: v(t) = sin(7t)u(t-3) 2. Relevant equations u(t) is step response 3. The attempt at a solution I know that taken alone the laplace of: sin(7t) is 7/(s^2+49) u(t-3) is (1/s)*(e^-3s) I don't understand how I would figure out the answer to this problem if I have u(t-3). For some reason, seeing the u(t-3) rather than u(t) is really making things hard to understand since I don't know how u(t-3) would be integrated. I considered setting t-3 =x which would yield: v(t) =sin(7x+21)u(x) v(t) = sin(7x)cos(21) + cos(7x)sin(21) Laplace = [7*cos(21) + s*sin(21)]/[s^2 + 49] but I don't know if I'm that's the right answer.