(1) The duck population near a small lake can be modelled by the function d(t) = 0.5(t2 + 8) (t + 4), where t is the time, in years, from now. (a) What is the current duck population? 16 ducks (b) Determine the rate of change of the duck population in 4 years. 44 ducks year (c) Determine the rate of change of the duck population when the population is 756 ducks. 194 duck/year 3