Help! Stuck on Dependent Current Source Problem

[Ankita0610]

I am stuck with this problem,the dependent current source is creating a big problem for me, please help.
I have attached the problem.

 

[smk037]

How are you trying to solve the problem?

Could help you more if you showed your attempt at the solution.

 

[Ankita0610]

i am using the equation of underdamped series RLC circuit,the initial condition says that at t=0- inductor current is 0,so at t=0+ the inductor current will b 0,then what is the role of dependent current,and how to find the thevnin equivalent of the circuit,for getting a Req,so that i can find the time constant.