Solve LI + RI ' + I /C = E 0 e it ,

Solve LI^∼" + RI^∼' + I^∼/C = E₀e^iωt, i = √-1, by substituting l_p = Ke^iωt (K unknown) and its derivatives and taking the real part l_p of the solution l^∼_p. Show agreement with (2), (4). Use (11) e^iωt = cos ωt + i sin ωt; cf. Sec. 2.2, and i² = -1.