Given the electrical variables:
v = 50e^-1600t - 50e^-400t
i = 5e^-1600t - 5e^-400t

a. Determine the time constant of the circuit.
b. Calculate the initial voltage (v0) and initial current (i0) when t = 0.
c. Find the values of v and i when t = 1/800.
d. State whether the circuit is capacitive or inductive.