1. The problem statement, all variables and given/known data http://img707.imageshack.us/img707/8950/calculusisu.jpg [Broken] 3. The attempt at a solution Looking for some guidance for this problem, I will add information as i go along. I think the steps are: 1) Develop a formula that represents the cost 2) Find critical points 3) evauluate the critical points What i am unsure of is am i allowed to vary the length of the highway and gravel road? Im asked to maximize profit or i can minimize cost. Is this cost of operating or of construction as well? If its of operating only i can easily deduct the construction cost from the inital 7.8 million. Also if its of operating only, can i not say operate as fast as possible to reduce hours? Please advise thank you.