13. + -17 points My Note The population age 65 and over (in millions) of developed countries from 2005 through 2034 is projected to be f(t) = 3.567t + 175.2 (5 st s 35) where t is measured in years and t = 5 corresponds to 2005+. On the other hand, the population age 65 and over of underdeveloped/emerging countries over the same period is projected to be g(t) = 0.46t2 + 0.160 + 287.8 (5 sts 35). (a) What does the function D = g + f represent? The total population aged 65 and over of the developed and the underdeveloped/emerging countries. The difference in population aged under 65, between the developed and the developing/emerging countries. The total population aged under 65 of the developed and the underdeveloped/emerging countries. The difference in population aged 65 and over, between the developed and the developing/emerging countries. (b) Find D'(t) and D'(30). D'(t) = D'(30) = Interpret your results. The difference in population aged under 65 is falling at the rate of D'(30) million people per year in 2030. The difference in population aged 65 and over is falling at the rate of D'(30) million people per year in 2030. The total population aged under 65 is growing at the rate of D'(30) million people per year in 2030. The total population aged 65 and over is growing at the rate of D'(30) million people per year in 2030