Example 2.1
Example 2.2
Example 2.3
Example 2.4
Example 2.5
Example 2.6
Example 2.7
Example 2.8
Example 2.9 
Exercise 2.1
Exercise 2.2
Exercise 2.3
Exercise 2.4
Exercise 2.5
Exercise 2.6
Exercise 2.7
Exercise 2.8
Exercise 2.9
Exercise 2.10
Exercise 2.11
Exercise 2.12
Exercise 2.13
Exercise 2.14
Exercise 2.15
Exercise 2.16
Exercise 2.17
Exercise 2.18
Exercise 2.19
Exercise 2.20
Exercise 2.21
Exercise 2.22
Exercise 2.23
Exercise 2.24
Exercise 2.25
Exercise 2.26
Exercise 2.27
Exercise 2.28
Exercise 2.29
Exercise 2.30
Exercise 2.31