80.9 Chapter 9. Solutions by infinite series and Bessel functions. Excercise 10.6 at page 223

80.9.1 problem 1
80.9.2 problem 2
80.9.3 problem 3
80.9.4 problem 4
80.9.5 problem 5
80.9.6 problem 6
80.9.7 problem 7
80.9.8 problem 8
80.9.9 problem 9
80.9.10 problem 10
80.9.11 problem 11
80.9.12 problem 20
80.9.13 problem 21