3 Chapter 4

  3.1 problem 2
  3.2 problem 4
  3.3 problem 5.1
  3.4 problem 5.2
  3.5 problem 5.3
  3.6 problem 5.4
  3.7 problem 5.4
  3.8 problem 7.1
  3.9 problem 7.1