Part A: Modeling the Growth of a Population using First Order Differential Equations.
Let y(t) denote the size of the population (in millions) at time t (in years since the start of monitoring). Thus, y(0) represents the initial population size. The population growth is then denoted as dy(t)/dt, and the relative population growth as (dy/dt)/y(t).
Model I: the Exponential Model
Statement: "The relative growth of the population is constant": (dy/dt)/y(t) = k
or, equivalently,
"The population growth is proportional to the size of the population": dy(t)/dt = ky(t)
1. Consider the problem: dy(t)/dt = ky(t), k = 0.2, subject to the condition: y(0) = 1
a. Compute the values of the slope dy/dt for the y values in the table:
b. Use the results in the table to sketch the slopefield for the problem and sketch the population trajectory.