Question: The power delivered to an electric circuit is given by P = ei, where e and I are the instantaneous voltage and the instantaneous current in the circuit, respectively. The mean power, averaged over a period 2π/ω, is given by P_av = (ω/2π )∫ ^2π/ω ₀ ei dt. If e = 20 cos 2t and I = 3 sin 2t, find the average power over a period of π/4.