Sandy is a big Star Wars fan and buys a $20 ticket a week in advance to the premiere of the new movie. After arriving at the theater, she realizes she forgot the ticket at home and doesn't have time to go back and get it. Sandy can afford to buy another ticket for $20, but she decides not to because seeing the movie isn't worth $40 to her. This is an example of:

When a company produces and sells x thousand units per week, its total weekly profit is p thousand dollars, where upper p equals startfraction 800 x over 100 plus x squared endfraction . the production level at t weeks from the present is x equals 4 plus 2 t. find the marginal profit, startfraction dp over dx endfraction and the time rate of change of profit, startfraction dp over dt endfraction . how fast (with respect of time) are profits changing when tequals8?