Mathswatch homework someone please help me

Brainlest answer can you find the area and circumference of a circle given the radius or diameter? if its yes or no explain why

The graph shown is the graph of which function?

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.