Economic Principle on fuzzy profit by weighted average value

The well-known economic principle on profit states that the profit is maximum when the marginal revenue equals the marginal cost. We hereby present the case where the demand and the cost are polynomials in the demand quantity variable. The coefficients are trapezoidal fuzzy numbers, hence the demand and the cost are fuzzy numbers too. Since our goal is maximizing the profit, we have to choose a suitable defuzzification method. We use is the Weighted Average Value one, which is more general than others presented by several authors. The results we obtain are a generalization of the crisp case