Я почувствовала  себя гением, когда решила эту задачу =)))

A government plans the economy on the assumption that population, P millions, for the next 15 years can be modelled by the equation

P=60+0.02t^3-0.001t^4

when t=time in year

a) How large is the population expected to be in 10 years time?

b) At what annual rate is the population expected to be increasing in 10 years time?

c) During what period does the dovernment expect the annual rate of increase to be increasing?

А сегодня родительский вечер. Почувствовала себя одиноко.