1981-01-04 — Page 10

頁二第張三第一日九廿月一十年申庚歷复

WAH KIU YAT PO

報日僑華

1981

中學會考試題預習專欄

(2) products from various

sellers are differentiated.

(c) monopoly

日期星

them.

(十三)

王啓光

提供資料

經濟

明德出版社陳勵德

Economics (13)

K.K. Wong & L. T. Chan

(Mill & Dale Press Ltd.)

MARKETS

1. Perfect Competition

Perfect competition exists in a theoretical environment in which the following conditions are fulfilled: (a) large number of buyers

and sellers –

With a large number of buyers and sellers, the total transaction will be very great. This means that each of them cannot exert his personal influence on the market price of the product by increasing or decreasing its output. Thus in perfect competition firms must take the price at which they are to sell as fixed and the demand for the product of an individual. firm is perfectly elastic. (b) homogeneous product -

Under a perfectly competitive market situation, the product of any one seller must be identical with the product of any other seller. This means that buyers have no motive for preferring the product of one firm to another and if a firm

raised its price, its sales would fall to zero.

(c)free mobility of resources

This implies that each required factor of production must be perfectly mobile.

(d) perfect knowledge of the

market-

All buyers and sellers must possess full information of the commodity if the market is to be a perfectly competitive one.

(e) free entry by new firms-

There should not be any restriction for the entry of new firms into the market.

II. Imperfect competition

In real life situation, the conditions of perfect competition cannot always be met. Whenever one or more of the above requirements are not satisfied, the market is discribed as an imperfect on one. Imperfect competition can be classified into three types according to its degree of imperfection. They are: monopolistic competition, oligopoly and monopoly, (a) monopolistic competition

This has three fundamental

characteristics:

(1) there is a sufficiently

large number of sellers

so that each can act independently of the other firms.

(3) market entry of new

firms is relatively

easy.

In monopolistic

competition, individual sellers can have influence

over the market price. This is because when there is an large number of their products or services, the product of one firm is not regarded as a perfect substitute of another.

An example of monopolistic competition is to be found in the retail trade. The ease of entry in this business results in excess capacity and differentiation may take the form of difference of location (for instance, one shop being more conveniently situated for some people), the general attitude of the shopkeeper, and the extent of the service available.

Actually, there are various sources of differentiation such as actual physical difference, location, service. consideration, reliability, personal attitude, etc. In addition, price may affect the choice of products. since many buyers prefer those sellers who offer a lower price. Since differentiation of product is essentially created by branding and packaging. marketing activities play a major role in

monopolistic competition

in attracting customers to patronize a particular brand.

(b) oligopoly

This is a form of imperfect competition in which there are only a few producers as compared to perfect competition where there is a large number of producers. A general feature of oligopoly is that the price policy of a firm is influenced by that of its competitors. This can be subdivided into perfect and imperfect oligopoly. (1) perfect oligopoly-

In perfect oligopoly, the commodity is homo- geneous and consumers have no preference for the product of one firm. as compared with another. This results. that a price cut by one firm will lead to similar price cuts by other producers, Hence, the largest firm will usually become the price leader.

(2) imperfect oligopoly-

In this situation, some degree of differentiation exists between the products of different firms, Even

a slight differentiation in the product will make one product not a perfect substitute for another. Under these conditio s, competition tends to be very keen

and many firms may employ mass

advertising or price- cutting strategies.

不隨禮柯多新彩ÿ無報請遠 另報拜式采穎色任販就道 收附出印多雜華 § 歡近閱 費送版刷姿誌僑迎閱向户

In the strictest meaning meaning of the term, monopoly occurs only when there is one producer of a

commodity for which there is no substitue, a situation often referred to as absolute monopoly, This is quite rare în real life to have only a single producer of a product and even rarer to have no Substitute for the product at all. Thus the term monopoly is often used to describe forms of very imperfect competition as in the following situations: (1) when one firm or a

group of firms working together controls a large proportion of the total supply of a commodity. For instance, most of the world's supply of rubber comes from Malaya.

(2) when it is wasteful to

duplicate a given service as in the case of public utilities. (3) patent rights - a patent

is a grant to the inventor of a new machine or idea,

giving him

a monopoly of its use for a certain period.

(4) others – a producer's monopoly in the home market may be protected from foreign. competition by means

of a tariff on imports,

thus giving rise to a monopoly situation.

歷史

(=+)

明德出版社胡應亮提供資料

HISTORY (13)

Philip Y. L. Woo

MILL & DALE PRESS LTD.

It's Christmas, so we deserve a break. There's really no point hammering facts and details into your memory, I don't have a good memory, so I don't like people saying that a good history student is one with a super memory. It's like telling me in my face, "You should not have studied history at all, after I've spent so many years on it. So you have my guarantee here — think, reason, and analyse history, if you are doing this, you are.. going to be successful; perhaps years afterwards historians will write down your name in their books.

Actually history is about men. In the past, yes, but just as the present is becoming the past, and just as both we and historical figures áre human beings, there's no reason why the feelings of people in the past are not the feelings that we are having. I mean to say that history had once been part of the real world and although past events are now shadow, our feelings and acts and so on continuously help to make up that shadow, as the passage of time

日四月一年一八九一届公年十七國民華中 育教僑華

Of course there is the cert exam to sit for. So you have to prepare for it. But I hope you are not doing it just to make sure there's one more pass subject on your result slip. Sometimes it's difficult to understand why history has now become such a dull thing in secondary schools. Students take pride in being able to memorize names, years and so on. And above-all, in the ability to record these things like a computer. I think this is like putting the cart before the horse. Detalls are needed to give support or proof to causes! effects. If you study the bits and pieces, you will be blind to the general pattern, and then history will have turned you into a tape-recorder or something like that.

You should know that when writing a history essay, you need more than points to be successful. If the points are confused in your mind, and if you just write some of the words that those points contain, then the essay must be a confusing one. If one not knowing anything about history reads that eassy and is still at a loss about what you are saying, then the essay is a total failure. It fails to say to the reader ideas and so on clearly. You may think that to say to the reader clearly is a technique like driving a car. But basically it is not so. Whether you can write something clearly depends on the clarity of your thought, and that depends on how much you understand from history, If your English is poor, you cannot understand what the writer of a history book says, and if you don't

understand that, you cannot hope to write understandable things in an essay. This is why despite

much effort in memorizing points and facts, a student may. still find it difficult to write a. history essay. The reason is a lack of real understanding.. Unlike a mathematical problem, where you can give an answer like XYZ, a history essay requires explanations, elaboration and organization. Then the points you have memorized have to be digested thoroughly before they can be explained clearly in writing. Thus your history teacher always tells you to read up history books often. The reason is that only by so doing can you acquire how ideas are put in words, how points are expressed, and most important and basic of all, what a period of history is clearly all about In short, things that deepen your understanding of history. Language (in this case, English) is just the tool. The ability to use the tool comes from your mastery over history, your understanding of it.

So don't ever be greedy. Don't stuff as many points and facts into your memory as possible. In an exam, you may

flows. So human problems, plan, find it impossible to say all of sweat, anger, delight and success and failure are all there — in history. You study it and your understanding of life is better. I think this is the aim of studying history. People like to say difficult-to-understand

things to say what the study of history aims at. I don't believe

them, and what is more disastrous, you may find it very difficult to say just some of the points clearly. To put things in your memory is one thing; to express them in words (in a. controlled,, organized and clear way) is another thing. So if someone tells you, "I have a lot.

of ideas, but I just don't have words and phrases to say them",

don't believe him. He does not

really have ideas.

附加數(十三) 明德出版社寄彦俊提供資料 Add Maths (13) Shumi

C. Y.

MILL & DALE. PRESS LTD.

Complex Numbers (I).

Worked Examples:

1.

Express

1-cost-isint

in the form x+iy. Solution:

(1–cose)—isinė

(1-cose)-isinë

(1-co≤8)+isinə

(1-cog9)+isinė (1-cos0+isine

32

(1-cost) +sin 1-cos@+isine

2-2cash

1-(1-sin2g)+1(2singcos)

2-2(1–2sin2=)

Zeing(singicos)

4sin

sing (1+icots)-cor

2. Find the modulus and

argument of

Solution:

4+41

1+1

The polar form of 4+41

1/2(cos45+isin45)

4/201845°

The polar form of 1.4i

(cos30+isin30°)

#3

1830

4/2c134

2.6 15

Ans

Ans.

3. Find the locus of the

point z such that

122+1

!iz+1

Solution.

2.

Putting z=x+ly into the equation,

{T(x-iy)+1 [(2x+1)+12y (1-y)+1x

√(2x+1)2+4y2 √(1-y)2+x2

Squaring both si (2x+1)+4y

(1-x)

4x

?+4x+1+4y

4x487

Which is

locus of he

Exercise 7

aired

1. Express the following in

the form ̈x+iy:

5+41

(a)-5-41 (b)

1 c080-igine

15.

(c)

1+cosu-i sinë.

Find the modulus and.

argument of the following expression

·(c).

13

iNo3

(i+1)(2+1)

3-i cos+isint

op-ising

3. Find the locus of z such

that

報日僑華閱訂期長請

訂閱電話:5-229081內線3號

(a) Iz−1} + [Z+1} = 4

(b) 12+1}=}z−1}

If z=x+iy, and [z]=1', show that z.Z-1 where Z is the conjugate of z.

If 0, x are also complex. numbers, and Uz+x70,

KZ+9 find the value of

全經包專新歷 僑濟羅刋聞史 稱報萬豐翔悠 許導有富實久

Page 10Page 11