Chapter 15
Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964

15.1 Exercise 5, page 21
15.2 Exercise 6, page 25
15.3 Exercise 7, page 28
15.4 Exercise 8, page 34
15.5 Exercise 9, page 38
15.6 Exercise 10, page 41
15.7 Exercise 11, page 45
15.8 Exercise 12, page 46
15.9 Exercise 17, page 78
15.10 Exercise 18, page 82
15.11 Exercise 19, page 86
15.12 Exercise 20, page 90
15.13 Exercise 22, page 99
15.14 Exercise 23, page 106
15.15 Exercise 24, page 109
15.16 Exercise 25, page 112
15.17 Exercise 26, page 115
15.18 Exercise 35, page 157
15.19 Exercise 37, page 171
15.20 Exercise 38, page 173
15.21 Exercise 39, page 179
15.22 Exercise 40, page 186
15.23 Exercise 41, page 195
15.24 Exercise 42, page 206
15.25 Exercise 43, page 209