6. A profit-maximizing monopoly faces an inverse demand function described by the equation

p(y) = 40 y and its total costs are c(y) = 7y, where prices and costs are measured in dollars. In the past it was not taxed, but now it must pay a tax of 6 dollars per unit of output.What is the deadweight loss resulting from the tax (not the deadweight loss due to the monopoly)?