0 points: Chapter 4, section 1: Exercise 0

0 points: Chapter 4, section 1: Exercise 1

2 points: Chapter 4, section 1: Exercise 2

0 points: Chapter 4, section 1: Exercise 4

2 points: Chapter 4, section 1: Exercise 6

0 points: Chapter 4, section 2: Exercise 13

2 points: Chapter 4, section 2: Exercise 15

0 points: Chapter 4, section 2: Exercise 26

2 points: Chapter 4, section 2: Exercise 28