11 Chapter 8, Linear differential equations of order n. Section 8.9, Reduction of Order. page 572

  11.1 problem Problem 1
  11.2 problem Problem 2
  11.3 problem Problem 3
  11.4 problem Problem 4
  11.5 problem Problem 5
  11.6 problem Problem 6
  11.7 problem Problem 10
  11.8 problem Problem 11
  11.9 problem Problem 12
  11.10 problem Problem 13
  11.11 problem Problem 14
  11.12 problem Problem 15