I'm in 6th grade what is 9p=72 solved mentally

Which expression is equivalent to sq-80

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

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.