21 = kt Population of the world, (x) is assumed to be a continuous variable at time / years. The rate of increase of x due to birth is ax and the rate of decrease of x due to death is Bx, where a and B are positive constant. a. By applying differential equation concept and assuming a = 0.060 and B = 0.040. Show the population of the world (x) double itself in approximately 35 years. Justify your answer. b. By using appropriate scale, draw the graph of world population growth