Martin Seligman's theory that people become anxious and depressed because they believe that they have no control over the stress in their lives, is called:

Donald was arrested for murdering an acquaintance. at the trial, donald takes the stand and testifies that he and the victim knew each other. he admits that they would drink and use drugs together. one night while partying, donald explains in his testimony, an argument got out of hand during a card game. donald explains that the victim accused him of cheating and pulled out a knife on him and started swinging it in the air. donald said that he had no choice but to pull out his gun and shoot the victim. the jury convicted donald of manslaughter. who would argue that donald weighed the potential costs and benefits of shooting the victim and decided to pull the trigger as a result of free will? a. a rational choice theorist b. a critical criminologist c. a conflict theorist d. a positivist

After 20 minutes of waiting outside the baggage claim area for your friend to pick you up, you decide to go inside the airport terminal and phone her. standing a short distance from you is a kind-looking older woman. "would you mind watching my luggage so i can go make a quick phone call? " you ask politely. "i'd be happy to watch it for you," she replies, "my ride is not coming for another half-hour." when you return less than five minutes later, the old lady and your luggage (including your laptop) are gone. this example illustrates one of the problems associated with: ethnocentrism. the "feel good, do good" effect.the rule of reciprocity. an implicit personality theory.

What does the delta symbol represents in this equation