1.12 Chapter 2. Linear Equations of Higher Order. Section 2.6 (Forced oscillations and resonance). Problems at page 171

1.12.1 problem 1
1.12.2 problem 2
1.12.3 problem 3
1.12.4 problem 4
1.12.5 problem 5
1.12.6 problem 7
1.12.7 problem 8
1.12.8 problem 9
1.12.9 problem 10
1.12.10 problem 11
1.12.11 problem 12
1.12.12 problem 13
1.12.13 problem 14
1.12.14 problem 15
1.12.15 problem 16
1.12.16 problem 17
1.12.17 problem 18