4.19 Chapter 9.1, The Phase Plane: Linear Systems. page 505

4.19.1 problem 1
4.19.2 problem 2
4.19.3 problem 3
4.19.4 problem 4
4.19.5 problem 5
4.19.6 problem 6
4.19.7 problem 7
4.19.8 problem 8
4.19.9 problem 9
4.19.10 problem 10
4.19.11 problem 11
4.19.12 problem 12
4.19.13 problem 13
4.19.14 problem 14
4.19.15 problem 15