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

19.1 problem 1
19.2 problem 2
19.3 problem 3
19.4 problem 4
19.5 problem 5
19.6 problem 6
19.7 problem 7
19.8 problem 8
19.9 problem 9
19.10 problem 10
19.11 problem 11
19.12 problem 12
19.13 problem 13
19.14 problem 14
19.15 problem 15