Use the Laplace transform to solve the given initial-value problem. Use the table of Laplace transforms in Appendix III as needed.
y'' + y = f(t), y(0) = 1, y'(0) = 0, where
f(t) =
1, 0 ? t < ?/2
sin(t), t ? ?/2
y(t) =( )+( )u(t-(pi/2))