Form 1 Mathematics Chapter 2 and Chapter 4

 Folder ◦ Today  WB (P.77, 80, 81) ◦ Today  SHW (III) (Chapter 4) ◦ 14 Nov (Wednesday)  Open Book Quiz (Chapter 4) ◦ 14 Nov (Wednesday)  Close Book Quiz (Chapter 4) ◦ 21 Nov (Wednesday)  You must hand in on time!

Ronald HUI  A Sequence is a group of numbers with number pattern.  Each number in the sequence is called a Term.  The first one in the sequence is called the First Term.  In the sequence, 2, 4, 6, 8, 10, …  2 is the first term, 4 is the 2 nd term, 6 is …  The general term ( 通項 ) is 2n or a n =2n

Ronald HUI  P.176 Questions 8-10: Find the first 3 terms of the sequence:  8. a n =n+4 a 1 =1+4=5; a 2 =2+4=6; a 3 =3+4=7  9. a n =n/3 a 1 =1/3; a 2 =2/3; a 3 =3/3=1  10. a n =20-3n a 1 =20-3(1)=17; a 2 =20-3(2)=14; a 3 =20-3(3)=11

Ronald HUI  P.176 Question 14: The general term of a sequence is 9(n+6). Find the first term, the 6 th term and the 10 th term of the sequence.  General term: a n = 9(n+6)  First term = a 1 = 9(1+6) = 9 (7) = 63  6 th term = a 6 = 9(6+6) = 9 (12) = 108  10 th term = a 10 = 9(10+6) = 9 (16) = 144

Ronald HUI  P.176 Question 15: The general term a n of a sequence is n(n+3). Find the first 5 terms and the 20 th term of the sequence.  General term: a n = (n)(n+3)  1 st term =a 1 = (1)(1+3) = 1(4) = 4  2 nd term =a 2 = (2)(2+3) = 2(5) = 10  3 rd term =a 3 = (3)(3+3) = 3(6) = 18  4 th term =a 4 = (4)(4+3) = 4(7) = 28  5 th term =a 5 = (5)(5+3) = 5(8) = 40  20 th term =a 20 = (20)(20+3) = 20(23)=460

Ronald HUI  P.176 Question 17b: Consider the sequence 6, 12, 18, 24, 30, … Use an algebraic expression to represent the general term a n of the sequence  n = 1, 2, 3, 4, 5, ……, n  a n = 6, 12, 18, 24, 30, ……, ??  a n = 6n

 Pages of WB 1A ◦ Questions  Page 175 of Textbook 1A ◦ Questions

Ronald HUI  A function is an input-process-output relationship between numbers.  For each input, there is one (and only one) output.  Sequence a n = 2n is a function.  Formula A =  r 2 is a function.

 Page 180 of Textbook 1A ◦ Questions  Pages of WB 1A ◦ Questions 1 - 5

 Result of Close Book Quiz ◦ Full mark: 40 and 10 bonus ◦ Highest: 37 ◦ Lowest: 9 ◦ Average: 20 ◦ Number of students between 10 – 19: 16 ◦ Number of students between 6 - 9: 1  Major Problems ◦ Most of you just marginally passed ◦ Wrong calculation! ◦ Careless mistakes!

 Result of Close Book Quiz  4 th place (6):CHOI King Shing, Walker NG Qiu Lun Marco TANG Yiu Cheung Harald WONG Pui Yin, Paul WU SHAN Hao Yi YEUN Tin Wai Timmy  3 rd place:CHEN Yi, David  2 nd place:LI Ming Chun Edward  1 st place:LI Sai Kong Congratulations!!! Well done!!!

 Today last lesson + afterschool (maybe)  The following students must attend:  Close Book Mark < 16  1, 10, 11, 16, 26, 36  Others are welcome to join.

 SHW (III) (Chapter 4) ◦ 14 Nov (Wednesday)  Open Book Quiz (Chapter 4) ◦ 14 Nov (Wednesday)  Close Book Quiz (Chapter 4) ◦ 21 Nov (Wednesday)  You must hand in on time!

Good Luck! Enjoy the world of Mathematics! Ronald HUI