problem0():
  Compare exponential and logistic growth
  Graphics saved as "problem0.png"

problem1():
  compare logistic and exact solution
  Graphics saved as "problem1.png"

problem2():
  compare rk2 estimate and exact logistic solution
  Graphics saved as "problem2.png"

problem3():
  Use Euler to solve the flame ode
  Graphics saved as "problem3.png"

problem4():
  Use solve_ivp() to solve the flame ode
  Graphics saved as "problem4.png"

problem5():
  Use euler_solve() to solve the pendulum ode
  Graphics saved as "problem5.png"

problem6():
  Use solve_ivp() to solve the pendulum ode
  Graphics saved as "problem6.png"

problem7():
  Third order ODE
  Graphics saved as "problem7.png"

problem8():
  Lorenz equations
  Graphics saved as "problem8.png"

problem9():
  Solve the Arenstorf ODE with solve_ivp()
  Graphics saved as "problem9.png"