RL circuit differential equation

[yellowmania]

Have been given a few practice questions to work on but have no idea where to start, im quite confident i Can do the main maths behind it eg general and complimentary solution but I'm struggling to get from this start to that point! Any help would be greatly appreciated thanks

Find the current in an RL circuit when
R=10 ohms
L= 1 henry
V(t)= 30cos(pi*t)

 

[godfreyl]

Are the R and L connected in series or parallel?

 

[ahmad1954]

just kvl on circuit and solve differential equation: v(t)=Ri+L(di/dt)