Soal latihan UTS tahun lalu nih. 5-year projection of population trends suggest that T years from now, the population of a certain community will be P(T)=T^3+9T

Soal latihan UTS tahun lalu nih. 5-year projection of population trends suggest that T years from now, the population of a certain community will be P(T)=T^3+9T^2+48T+50 thousand. A. at what time during the 5-year period will the population be growing most rapidly? B. at what time during the 5-year period will the population be growing most least rapidly?