6. When working with applied optimization type problems, it is not enough to only look at the critical points; why? Please find, and provide a complete solution to, one example of an applied optimization problem related to business in the exercises of the textbook or previous exams.

7. Define the definite integral and discuss how we evaluate by hand. Please find, and provide a complete solution to, one example of a definite integral involving substitution and relating to a business application (average cost for example).