6.1 problem 7.2
6.2 problem 7.2 (c)
6.3 problem 7.4 (a)
6.4 problem 7.4 (b)
6.5 problem 7.4 (c)
6.6 problem 7.4 (d)
6.7 problem 7.4 (e)
6.8 problem 7.4 (f)
6.9 problem 7.4 (g)
6.10 problem 7.4 (h)
6.11 problem 7.5 (a)
6.12 problem 7.5 (b)
6.13 problem 7.5 (c)
6.14 problem 7.5 (d)
6.15 problem 7.5 (e)
6.16 problem 7.5 (f)
6.17 problem 7.5 (g)
6.18 problem 7.5 (h)
6.19 problem 7.5 (i)