For the circuit of given figure:
a. Determine t.
b. Write the mathematical expression for the current iL after the switch is closed at t = 0 s.
c. Write the mathematical expressions for vL and vR after the switch is closed at t = 0 s.
d. Determine iL and vL at t = 1τ, 3τ, and 5τ.
e. Sketch the waveforms of iL, vL, and vR for the storage phase.