頁二第張七第 日八初月二年午戊屬夏

WAH KIU YAT PO

報日僑

11 4 16 *

1978

|中場會考試題領習專欄

The circle is

2

(x h)2 + (y - k)2

-

Also, (h, k) is on 3x-4y=0

Since the circle passés through. (0,0)

+

= 25

h)2+(0 - k)2 = 52

(1)

3h 4k

新數學 廿四 番榮家

From (2)

MODERN MATHEMATICS (24)

Answers to Test Nine Section A

Substitute into (1)

k =

= + 碌

The circle is

25

(2)

(x-4)2+(y 3)2= 25

or

+ 3)2

= 25 (ans.)

As shown in the figure

AC AL BQ

AB a + b

BC b

= √AB2 - BC2

(*

?

rt.

ABC

+ b)2-

-Maj2·

Hab

ab (Ans,)

But PG AC

•PQ=

2/ab (Ans.)

2. Let the length of each side of the square be a and that of the equilater.. al triangle be b

48 - 3b

Area of the square Area of the triangle

+(b)(b)sin60°

-2/2

(Ans.)

3.

2kx + (4k

X

19-20 13

n+1

12 2012-1

11

1

210 (Ans.)

8. Scos20

-3sin@cose 3sin@cose

= 4(sin e + cos28) Cos20

38inecose-4sine

(cose-4sine)(cosê+sine)=0

(COB✪ - 48ine = 0 tane - 1

@ -14°2′ or 194°2!

(Ans.)

cose + Bánе = 0

tane =-1

3)=0

-135° or 315°

(Ans.)

Since the equation has

no real roots,

(2k)2 - 4(1)(4k-3) 0

-

16k+ 120

- 4k+:30

(k-1)(k−3)<0

1 < k < 3 (Ana.)

(2x −1)2 + 4(3-y)2 = 16

2(x-

1) 24(y-3)2- 16 2)2+ 4 (y-3)2 (x - ¿)2 + (y-3)2

4(x

= 16

22

It is a circle with centre at (1, 3) and radus 2 units..

(3)

5. ā =

21 +31

no

(31 +53)

+ n(41

+ 73) (3m. + 4n)Ï

+ (5m + 7n)J

3m +40= 2

(1)

50+ 7n3

.(2)

7x(1)

4x(2)

** 2 (Ans.)

Substitute into (1)

| 3(2) + 4n = 2

n-1 (Ans.)

6. Let the centre of the

required circle be (h,k)

Section B.

9(a) Since k = 2n

the statement is found to true only when

2,4, .... 2000

A is the correct ens.

(b) When n = 1

=

12 is divisible

by 12

it is true when

n = 1 Assume5 7 is divisi- ble by n when n = k,

12 N

where N is an integer

When n k+ 2

sk

+2

52.5+ 72 7 52(12N-

128 (72 52k 52.12N + 24.7k 2.pky

= 12(25N + 2.

is divisible by 12 Since the statement is. true when n1, and if it is true for n = k, then

it is also true for n=k+2, therefore, the statement

is true for all odd inte-

gera n.

經濟與公共事務(廿四)

·孔繁盛、

Economic and Public Affairs

(34) Education in Hong Kong

(continued)

5. Technical Institutes

【四期星

The government has given considerable priority in recent years to the provis... ion and building of techni- oal institutes, most of ki whose courses are designed for Form 3 leavers..

At present, there are four technical institutes in Hong Kong. They are the. Morrison Hill Technical Institute, the Kwai Chung. Technical Institute, and the Haking Wong Technical: İnati- tute.

The institutes offer a wide variety of courses, including mechanical, elec- trical, electronic, building and civil engineering; plas- tica shipbuilding and ship repairs textiles and cloth- ing; commerce; and service. industries, including hotel keeping and tourism,

All these courses are.

provided on a full-time,

blook release, part-time day

or part-time evening basis. The institutes maintain close contact with industry. and commerce.

6. Post-Secondary Education

There are two post-second- ary collages registered with the Education Department under the Post-Secondary Ordinance. They are The Hong Kong Baptist College and The Hong Kong Shue Yan College.

The Hong Kong Baptist Col- lege was registered in 1970. It has four faculties arts business, social sciences, and natural sciences and en- gineering.

The Hong Kong Shue Yan. College was registered in 1976. It consists of three. faculties arts, social sciences and commerce.

7. The Hong Kong Polytechnic

The Hong Kong Polytechnic was formally established in 1972, when it took over the work of the former Hong Kong Technical College.

The polytechnic has 15 te- aching departments grouped under three divisions. They are Applied Science Division, Commerce and Design Division, and Engineering Division.

The polytechnic offers two year full-time courses lead- ing to a diploma, three year full-time courses leading to a higher diploma, and one- year full-time post-higher. diploma courses leading to an Associateship of the Hong Kong Polytechnic.

The University of Hong Kong

The University of Hong Kong was established in 1911 with a land grant from the government. Substantial government, grants are made towards the university's annual recurrent and non- recurrent expenditure.

The university offers und- ergraduate places in the following faculties: arts, science, medicine, engineer- ing and architecture, and social sciences and law/

It also offers a number of degrees of Masters and Doot- ors of Philosophy in certain fields for apsoially-qualif- ied and selected candidates, Its Department of Extra- Mural Studies also provides evening and day courses for adult students.

9. The Chinese University of

Hong Kong

The Chinese University of Hong Kong was inaugurated in 1963 as a federal university It is a self-governing cor- poration that draws ita income mainly from government grants, The university com- prises three constituent colleges Chung Chi, New Asia and United.

Following the enactment of a new Univeristy Ordiance in December, 1976, teaching methods at the university were ohanged to provide a balance between *subject-oriented' teaching and student-oriented teaching.

The university consists of four faculties arts, business, administration, science and social science. It also has the Gradiste School which offers instruction at post- graduate level through 17 divisions.

10. Teacher Education.

Except for technical teach- er training, teacher educat- ion is provided at the Educa- tion Department's three coll- eges of education – Grantham, Northcote and Sir Robert Black.

They offer two-year full-time courses for produ- oing non-graduate teachers

in primary schools and junior › forms of secondary schools. The college also have third- .

日六十月三年八七九一屦公年七十六國民華中育教華

year courses aimed at raising

the standards of teachers and

preparing them to teach the

new curriculum in junior secondary forms.

The

Technical teachers receivė training at the Hong Kong. Technical Teachers college, which is administered by the Education Department. college trains technical teachers for secondary schools prevocational schools and te- chnical institutes. The pollege also provides in-ser service courses of teacher training. A centre de being developed for technical

tenohers to gather and exch-

ange ideas.

數學 二十四女長波

Mathematics 24

Solution to exercise 10 Section B.

11.Solution:

Ans. (a)The cars meet at 9.50a.m.

(b)The distance from

I when the cars. meet is 25km. (c)The speed of the car returns to X is 75km/hr. and the speed of the car return to Yis 45km/hr.

12.Solution;

His sale for of the estate at a gain of 20% -$240000x4x(1+20%)

#$72000

His sale for of the estate at a loss of 15%. »$240000x x(1–15%)

$81600

His sale on the whole at gain of 10% 520 -$240000x (1+10%) -8264000

His sale for the remainder -$264000-$72000–681600.

-$210400

The gain % for the remainder part of the estate

110400-240000x(1–1–3)

-31

13.

240000x ( 1 −1-

Solution:

x100%

Let AB be the length of the shadow of the longer pole

AR 10

44

AB-7.5m. AG-(7.5-4.5)m

In AAGC

tane

8-30 58

LNCA-90°

-59

The bearing of the

shadow cast by the rope is N59°2:W or E.

Solution ZBAD-180

-84 *4-20

*-35o·

4x84-28°

In 4 ABC

BC

AC sin56' sinɓl"

sin61"

i.e. Bc ACsiu56′′

In AACD

CD

AC

ain28"- ain35°

i.c. cp ACsin28“

AOsin56

BC

sinól

CD

ACain28

sin55

ain56 sin

sin61 sin28 -1.16

Given: ABPC is a cyclic

quad. PXLAB

PYLBC; PZLAC

To prove:(a)ZPYX=ZPCA

Prove:

(b), Y, Z are

collinear.

(a)Since PXLAB; PY1BC; PZLAC

• £PXB=¿P¥B=90°.

ZPXB+LPYB=180*

(Given)

X, B, Y are coucyclic

opp. La supp.)

Similarly, P, Y, Z, C are concyclic..

¿PBX=/PCA (Ext. 4 cyclic

quad.)

¿PBX-ĹPYX (4s in the same

segment)

< PYX-LPCA

(5) ≤PCA÷4ZYP=180° (opp. 28

16,

cyclic quad

‚ĹPYX+ZZYP×180° (subst.)

Z are collinear (Adj. Za supp.).

Given: RC is the diameter.

of the circle

CE is the tangent of the circle at C. BC//AD

To prove BC AEBD

Proof:

Join DC AC and AB.

ZBDC-90 (4 in semi-circle) Since BC is the diameter and CE is the tangent at

C of the circle.

LBCE=90°

AD//BC (Given)

LAEC-90° (Int.

AD//BC)

i.e. ZBDC-ZAFC-90′′*

ZDBC-ZDCE (Z in alt.

segment)

/ ZACH=ZCDE (3rd 2 of 4)

BDC CED

are similar (Equiangular ás)

BD CE

(corr. sides,

BC CD

similar As)

Similarly, AACE are

CE AE

CD AC

BD AE AC

DE similar

(subst.

BC AE BD-AC

LCDE-LABC (Ext. 4 cyclic

quad,}

LCDE-4BCD (proved)

.*:/ABC=4BCD

.. AC-BD (Equal¿, equal

chords)

i.e. BC AE-BD2

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