1. John sells mugs. He believes that the demand for the (number or) mugs can be modeled by D(x) = 60 8):, where x is the selling price of a mug in dollars. a) (2 points) Write down the revenue function (dollars) in terms of x. b) (2 points) Ifthe unit cost of each mug is $4.00, write down the cost function (dollars) in terms of x. c) (2 points) Write down the prot function (dollars) in terms of x. d) (5 points) Use derivatives and algebra to find the price that maximizes prot. Use second derivative test to Show that the price you found gives the maximum prot. Show your work. Use your calculator only to do basic arithmetic