Ordinary Differential Equation

Use Laplace Transform to solve the following given initial value problem
1. y''-2y'+2y=cost where y(0)=1 y'(0)=0

2. y''+4y=1 for 0<= t < pi and y''+4y=0 for pi<= t < +inf where y(0)=0 y'(0)=1

3. y''+y=t for 0<= t <1 and y''+y=0 for 1<= t <+inf where y(0)=0 y'(0)=0