68.9 Chapter 4. Higher Order Equations. Exercises 4.1, page 141

68.9.1 problem 9
68.9.2 problem 10
68.9.3 problem 11
68.9.4 problem 12
68.9.5 problem 13
68.9.6 problem 14
68.9.7 problem 15
68.9.8 problem 16
68.9.9 problem 17
68.9.10 problem 20
68.9.11 problem 21
68.9.12 problem 22
68.9.13 problem 23
68.9.14 problem 25
68.9.15 problem 26
68.9.16 problem 27
68.9.17 problem 28
68.9.18 problem 29
68.9.19 problem 30
68.9.20 problem 31
68.9.21 problem 32
68.9.22 problem 33
68.9.23 problem 34
68.9.24 problem 35
68.9.25 problem 36
68.9.26 problem 44
68.9.27 problem 45
68.9.28 problem 46
68.9.29 problem 47