2.1.1 problem 1(a)
2.1.2 problem 1(b)
2.1.3 problem 1(c)
2.1.4 problem 1(d)
2.1.5 problem 1(e)
2.1.6 problem 1(f)
2.1.7 problem 2(a)
2.1.8 problem 2(b)
2.1.9 problem 2(c)
2.1.10 problem 2(d)
2.1.11 problem 2(e)
2.1.12 problem 3(a)
2.1.13 problem 3(b)
2.1.14 problem 3(c)
2.1.15 problem 3(a)
2.1.16 problem 4(a)
2.1.17 problem 4(b)
2.1.18 problem 4(c)
2.1.19 problem 4(d)
2.1.20 problem 5(a)
2.1.21 problem 5(b)
2.1.22 problem 5(c)
2.1.23 problem 5(d)