What value of a makes f(x)=x^2 +a/x have a local minimum at x=2

How do ocean currents affect temperature? check all that apply. they carry cold water from the poles to the equator and cool air over land. they flow north and then south below the equator. they flow south and then north above the equator. they move warm water from the equator to the poles and heat air over land. they move east to west and create prevailing winds. they move west to east and create seasonal winds.

Which are results of technological advances? increased people's exposure to new ideas created a global culture valued by people around the world brought harmony to diverse groups of people reduced the number of people living in rural areas

South america is located within which hemisphere?