Form 1 MathematicsChapter 2 and Chapter 4

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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 2nd term, 6 is … The general term (通項 ) is 2n or an=2n

Ronald HUI

P.176 Questions 8-10: Find the first 3 terms of the sequence:

8. an=n+4

a1=1+4=5; a2=2+4=6; a3=3+4=7

9. an=n/3

a1=1/3; a2=2/3; a3=3/3=1

10. an=20-3n

a1=20-3(1)=17; a2=20-3(2)=14; a3=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 6th term and the 10th term of the sequence.

General term: an = 9(n+6) First term = a1 = 9(1+6) = 9 (7) =

63 6th term = a6 = 9(6+6) = 9 (12) = 108 10th term = a10 = 9(10+6) = 9 (16) =

144

Ronald HUI

P.176 Question 15: The general term an of a sequence is n(n+3). Find the first 5 terms and the 20th term of the sequence.

General term: an = (n)(n+3) 1st term = a1 = (1)(1+3) = 1(4) = 4 2nd term =a2 = (2)(2+3) = 2(5) = 10 3rd term = a3 = (3)(3+3) = 3(6) = 18 4th term = a4 = (4)(4+3) = 4(7) = 28 5th term = a5 = (5)(5+3) = 5(8) = 40 20th term = a20 = (20)(20+3) = 20(23)=460

Ronald HUI

P.176 Question 17b: Consider the sequence6, 12, 18, 24, 30, … Use an algebraic expression to represent the general term an of the sequence

n = 1, 2, 3, 4, 5, ……, n an = 6, 12, 18, 24, 30, ……, ??

an = 6n

Pages 83 - 84 of WB 1A◦ Questions 1 - 4

Page 175 of Textbook 1A◦ Questions 1 - 12

Ronald HUI

A function is an input-process-output relationship between numbers.

For each input, there is one (and only one) output.

Sequence an = 2n is a function. Formula A = r2 is a function.

Page 180 of Textbook 1A◦ Questions 9 -12

Pages 86-87 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 4th place (6): CHOI King Shing, Walker

NG Qiu Lun Marco TANG Yiu Cheung Harald WONG Pui Yin, PaulWU SHAN Hao YiYEUN Tin Wai Timmy

3rd place: CHEN Yi, David 2nd place: LI Ming Chun Edward 1st 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