Solve these 2 questions a and c( trigonometry sinplify)

Ineed if you could explain and give me the answer you! this needs done

How can you tell when x and y are not directly proportional?

The american academy of pediatrics wants to conduct a survey of recently graduated family practitioners to assess why they did not choose pediatrics for their specialization. provide a definition of the population, suggest a sampling frame, and indicate the appropriate sampling unit.