Solving for the profit maximizing quantity, price and optimal profit level using EXCEL (refer to the Extra Credit Example file attached with this problem set)

A firm's demand function is Q = 16 - P and its total cost function is defined as TC = 3 + Q + 0.25Q². Use these two functions to form the firm's profit function and then determine the level of output that yields the profit maximum. What is the level of profit at the optimum?