(c) Use your formula for E to determine the selling price that would have resulted in the largest annual revenue. What, to the nearest $10 million, would have been the resulting annual revenue? Recall that the price that results in the largest revenue must be at unit elasticity, where E = 1. Since we already found E = 10p -10p + 4,540' set E = 1 and solve for p. 10p = 1 - 10p + 4,540 10p = p + 4,540 P = 4,540 P = Therefore, maximum revenue occurs with a selling price of $ per phone