85.9 Chapter two. First order and simple higher order ordinary differential equations. A Exercises at page 37

85.9.1 problem 1 (a)
85.9.2 problem 1 (b)
85.9.3 problem 1 (c)
85.9.4 problem 1 (d)
85.9.5 problem 1 (e)
85.9.6 problem 1 (f)
85.9.7 problem 1 (g)
85.9.8 problem 1 (h)
85.9.9 problem 1 (i)
85.9.10 problem 1 (j)
85.9.11 problem 1 (k)
85.9.12 problem 1 (L)
85.9.13 problem 2