1. Determine Laplace transform of (2-2e^-4t)u(t)
2. Determine if x(t) = 9cos(2t)+4sin(pi t) is periodic; if periodic, calculate the period.
3. Compute the inverse Laplace transform of X(s)= (s+2)/(s^2+ 7s + 12).
4. Determine if y(t)=cos(x(t)) is linear, time-invariant, and/or causal