Homework # 4 Hand-in (Due Tuesday, Oct. 20 - 2pm): Sec. 4.1 - 9 Sec. 4.2 - 25 Sec. 4.3 - 12 (this introduces an important definition) Additional Problems: Sec. 4.1 - 5, 7 Sec. 4.2 - 8, 14 Sec. 4.3 - 10, 15 Sec. 4.5 - 5, 6