4.1 problem 1(a)
4.2 problem 1(b)
4.3 problem 1(c)
4.4 problem 1(d)
4.5 problem 1(e)
4.6 problem 1(f)
4.7 problem 1(g)
4.8 problem 1(h)
4.9 problem 4(a)
4.10 problem 4(b)
4.11 problem 4(c)
4.12 problem 4(d)
4.13 problem 4(e)
4.14 problem 4(f)
4.15 problem 5
4.16 problem 6
4.17 problem 7
4.18 problem 8
4.19 problem 9
4.20 problem 10(a)
4.21 problem 10(b)
4.22 problem 10(c)
4.23 problem 11
4.24 problem 12
4.25 problem 13
4.26 problem 15
4.27 problem 21
4.28 problem 23
4.29 problem 24
4.30 problem 26
4.31 problem 28