二十{〇九九- )年九十七國民中

育收日五十月十年午庚腊夏

1991 中學會考預習專欄

明德出版社

MILL & DALE PRESS

Additional Mathematics (9)

'From (3)

(2) x (4)

邹日僑華

Exercise 9

六期星

日一月二十(〇九九一)年九十七國民華中 (ad

A variable toint P on the parabola 16x, find the locus of the mid- point of the line segnent joining (3, 4) and P

2. The sum of square of distance from a moving point P to the line.xy0 and a point (1), 155 sq. units. Find the locus of P.

31 It is a variable, point on the curve. 5. The feet of perpendicular. from H to the axes are A and B. Find the locus of the mid- coint of AB.

412 = 1612x

16 32% 41-160

2. Let (x, y) be the coordinates of

Square of distance from P tó ene line x › ya 0 is.

Scuore of distance from P to e. Dofnt. (r. 1) is

Dy+34}{ x2-

3x + 3y +6×3y?-32x3-32y3-32×3y-32xy? +120x+120y-32xy = 0

(Ans.)

Let ( be the coordinates of k' be the mid-point of A, By équation of the variable" line. The Coordinates of A is (k + 3, k), the coordinates of P IS (A. 2k, k)" (4-2k)

大埔津中 英文文憑教師

91年二月二日到職,應徵者講親繕 履歷附近電話函大埔富善邨圓玄 學院第二中學校長收或電6616038 鄧小姐洽

沙田津中

英文學位教師

申請人須於一九九一年一月初到 職,任教中二及中四英語。有意 者請速致電6951158 黄小姐接洽:

Revision Exercise 9

Coordinates Geometry 11 - Loci

Worked Example

1. A straight line L which passing through a fixed point (0, 4), cuts the circle xy at two points. P and PP is another point on 1 between

· such. that: PPDB Find the equation of locus of the print P.

Solution

"Let

be the

coordina respec

Put

4y #

Put (5) in (7)

-1

(6)

4. Given three points A(3, 5), (0, or, £15, 3). From a point P, PA, PB and PC are joined, [ PA PB PC, find the locus. of P..

S. Avariable line parallel to the x-axis cuts the curve x = y at

The equation of Tucus of P is

·DE

Fans.

2. Find the locus of a point, such that the mid-point of P and ALT.- lies on the cirule‹ x2 + y2.

Solution:

Let #ix, y) be a paint the locus. Then the midpoint of PA is (*44 244)..

Put the mid-point in the equation

A and the line x + 2y - 40 at B. Find the focus of the mid-point of AB

6. A(30) and R(5, 0) are two fixed points and 0 is the origin. P is a noving point such that OPB is a right angle. find, the equation.or the locus of the mid-point Q OF AN

7. The feet of perpendicular from a moving paint P to the x-axis and y-axis are A and B respectively. If CA OB find the locUE OF P

Solution to Exercise 9

3x2+3y2+2xy=4x+4y-† =10 (Ms.)

3. Let (h, k) be the coordinates of HÒ Then (n. 01, (0,8) are .the coordinates of A and B. respectively. The mid-point of AB is

2y

Th, kt lies on, 2x 2

5

Let ki be the coordinates of

PA PB.

The mid-point of P. and 13, 41s

The locus is e circle (1-1), radius 16.

certre

(Ans.)

4:0 (0)

satisfying

above system

both

the solut

(x-3)

The Coordinates of

(Ans.)

be the

5. Lot

(a, b). coordinates of P.-Q respectively.

شهد

Slope, of ap

Slope of Pi

.5(2x)

22x + 24 =0

(Ans,

7. Let (x, y) be the coordinates of P.

Coordinates uf

coordinates of 8:1s (q, y),

DA • QB = b

•Required equation; xy=

***7*+k=0 has no real foot

10

49-4 CO

港東津中誠聘

(1)二級文員:男或女,入薪點配合經 驗,盡早上班

(2)男數學教師:教育學院或大專畢

業。 月二十一日到廠。

·請電:5784138 校長洽

誠聘福利工作員

( 何文田區 )

應徵者需年滿廿一歲,會考五科合 格,包括英文課程乙,以上職位 需輪班工作。

1993中坐者考預習專欄,

ان من السياسة

WILL, &COYALE PHESS.

Mathematics (9)

Exercise 9. Inequal

Section A

Solve the inequal

(Ax+3)

Inequales.

(a) Find,

Solve the simultaneous inequalities.

J. Solve the preq

2x + 1

Solve the inequal

HONG

x+2y 18

(b). Hence, find

(i) the marisum value of 2x-y+5 (ii), the minimum value of xt2y+^.

satisfying the inequalities in (a):

Solutions to exercise 9

4. 7(4x-3142 & 3 (2x+3)- —

Multiply both sides by 4

-5(4x-3)+8612x+3)-1 20x-15+8 12x+18:1 8x 24 X 3

3x-9 -2x+2

11

√(x+1) | | 3x+5)

Multiply both sides by 12-

4(x+1). > 3(3x+5)

4x+49x+15

5x11

11

Since there is NO real, number which (a)

is less than

and also greater

.6

OF

than Thus, there is NO SOLUTION- For the given. inequalities.

system

72+19x-3x-

Thus,

́8+3X), 0°

B+3xK

ས་

有意者請詳履歷,近照寄九龍何文

田忠孝街 89 號人事主任收

北角津中誠聘

(日中四英文及地理學位教師一名,

(2)中四中文及中央學位教師一名! 請總履歷附近照電話函本報借箱

1509

助教、

急聘

半日代課 54

Solve the inequali

72+ 19x8x* K

Solve the inequality

36x* - 69x * 30->

Section 8

7. Find the range of k such that

(a) the equation x2+7x+k=0

real root,

(b) the equation x-(k+1)x+40

two real roots,

B. (a) Fine, graphically, the soly

of the inequalities.

x + 2y 8

6.

$121 = *+thy #

Multiply both sides by. 3(2x-1)-2(x+1) 25:

6x-3-2x-2 % 5

(1) and (2)

***[Ans:)

The solution for the first system of Inequalities is x 9 and there 75 no solution for the second system of inequalities.

···36x69x+30 >0;

| 3(12x2-23x+10) 2.0

(4x-5)(3x-2) 0.

(Angl

-(k+11x+4ND has two real roots

As shown in

JES

[Ansu

Figura the points

sets of x, given system

in the pace agion (including the

LIBRA

AONG PUBLIC

(b) Hence, ing the maximum

the

expression

1991中學會考預習專欄

3x+6

is always true.

Economic & Public Affair

Thus,

The points satisfying the given inequalities are the dots marked ig - the above graph. (Note: (2, 0), 14, 7) and (6, 6) are not included as x+2y18) (b).

The maximun value of 2x-y satisfying the inequalities in (al

2021

The required maximum value

of

maximum constraints given in (a) when

under

the

of x12y

the inequalities in

X=4 and 2.

(a)

Maximum value of 2x+3y is

2.4-2(2)

214)+3(21 14.

Maximum value of -2x+3y+10- Satisfying

The required minimum value

(Ans.)

the inequalities is 14. + 10,

Company

each partner has limited power

each partner shares som duties

accounting

Tawyer

unlimited and may be perpetual

shares are

transferable

Shareholders contrul through the Board of Directors

salaried managers

factories

Hong Kong Telephone Company Limited

柴灣區不牟利幼稚園聘基督徒半日助 教多名,半日代課助教一名薪優十二 月到幟,有意請電: 5580299 主任

明池出版社

MILL & DALE PRESS

Business limits (3)

Comparist

Types of

ownership

Compare

急聘會計

1. Ease of formation

̇九龍某校

2. Cost of formation

little cost

誠聘會計

Sole Proprietorship

very easy and few Tegal procedures

little cost

Partnership

easy but have to draw an article of partnership

difficult and a lot of legal procedures. needed!

high cost because of incorporation, and legal fees

Types of

ownership

Solà Proprietorship

Compate

'1. Kwok

12. Continuity;

limited and based on health of the owner.

13. Transfer of

Ownership

at will of the owner-

limited

14. Control of the firm

Limited. Company

the owner has full. power

15. Owner(s) and

anager(s)

owner manager.

16, Common examples

Barber shop

3. Personal incentive

of owner(s)

very high

Tow

有意者請電三八六三一四九治

Credit standing

"lowest

-nigh

5. Liability of

owner(s).

unlimited liability

unlimited liability

limited liability

Types of

limited

company

Private limited company

6. Size

sma}}

誠聘學位教師

7. Opportunity for

larger

possible

unlimited size

possible.

Cumpare

No. of shareholders.

employees to be

九龍城區中學誠聘各科學位教 師多名,有意請繕體歷相片寄 本報信箱1149號。

prijsoted as owner(s).

8. Managerial

efficiency

9. Freedom of action

10. Promptness of action

11. Ease of dissolution

inforio

immediate

very easy

very free

better because of division, of labour Among partners

some limitation

slower

high

such himitation:

slorest

0a5y

difficult and have to Follow Tegal procedures

Public limited company

No. of directors

Iranster of ownership

Secrecy

Fundraising

Capital requirement

12.00 50

1

privately transferred

not required to publish accounts on the, pross

mainly by existing shareholders

-Sea Her

2 to unligited

at least 2

in stock exchange market

required to publish operation results on the press.

inviting public to buy shares

Färger

Page 30Page 31

Share This Page