20.5 Chapter 1, First-Order Differential Equations. Section 1.9, Exact Differential Equations. page 91

20.5.1 problem Problem 1
20.5.2 problem Problem 2
20.5.3 problem Problem 3
20.5.4 problem Problem 4
20.5.5 problem Problem 5
20.5.6 problem Problem 6
20.5.7 problem Problem 7
20.5.8 problem Problem 8
20.5.9 problem Problem 9
20.5.10 problem Problem 10
20.5.11 problem Problem 11
20.5.12 problem Problem 12