4.10 Chapter 3, Second order linear equations, section 3.6, Variation of Parameters. page 190

4.10.1 problem 1
4.10.2 problem 2
4.10.3 problem 3
4.10.4 problem 4
4.10.5 problem 5
4.10.6 problem 6
4.10.7 problem 7
4.10.8 problem 8
4.10.9 problem 9
4.10.10 problem 10
4.10.11 problem 11
4.10.12 problem 12
4.10.13 problem 13
4.10.14 problem 14
4.10.15 problem 15
4.10.16 problem 16
4.10.17 problem 17
4.10.18 problem 20
4.10.19 problem 29
4.10.20 problem 30
4.10.21 problem 31
4.10.22 problem 32