World Population The total world population is forecast to be
P(t) = 0.00084t³ − 0.0716t² + 0.97t + 6.04 (0 <= t <= 10)

in year t, where t is measured in decades, with t = 0 corresponding to 2000 and P(t) is measured in billions.
(a) World population is forecast to peak in what year? Hint: Use the quadratic formula. (Remember that t is in decades and not in years.