已知椭圆x225+y29上一点P到两焦点距离之积为m，则当m取最大值时

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已知椭圆

上一点P到两焦点距离之积为m，则当m取最大值时，P点坐标______．

答案

设椭圆的左右焦点为F₁、F₂

根据椭圆的定义，可得|PF₁|+|PF₂|=2a=10

∵|PF₁|•|PF₂|≤[

（|PF₁|+|PF₂|）]²=25

当且仅当|PF₁|=|PF₂|=5时，P到两焦点距离之积为m有最大值为25

∴当m取最大值时，P点位于短轴的顶点，其坐标为（0，±4）

故答案为：（0，±4）

选择题

____________ the small closet, there's a small bed.[ ]

A. Beside

B. beside

C. Blue

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填空题

Part 1

·Read the followingpassages, eight sentences have been removed from the article.
·Choose from the sentences A-H the one which fits each gap.
·For each gap (1-8) mark one letter (A-H) on the Answer Sheet..
To understand the nature of the liberal arts college and its function in our society, it is important to understand the difference between education and training.
Training is intended primarily for the service of society; education is primarily for the individual. Society needs doctors, lawyers, engineers and teachers to perform specific tasks necessary to its operation, just as it needs carpenters and plumbers and stenographers. (1) And these needs, our training centers — the professional and trade schools — fill. But although education is for the improvement of the individual, it also serves society by providing a leavening of men of understanding, of perception, and wisdom. (2) They serve society by examining its function, appraising its needs, and criticizing its direction. They may be earning their livings by practicing one of the professions, or in pursuing a trade, or by engaging in business enterprise. They may be rich or poor. (3) Without them, however, society either disintegrates or else becomes an anthill.
The difference between the two types of study is like the difference between the discipline and exercise in a professional baseball training camp and that of a Y gym. In the one, the recruit is training to become a professional baseball player who will make a living and serve society by playing baseball. (4) The training at the baseball camp is all-relevant. The recruit may spend hours practicing how to slide into second base, not because it is a particularly useful form of calisthenics but because it is relevant to the game. (5) Similarly, the candidate for the pitching staff spends a lot of time throwing a baseball, not because it will improve his physique — it may have quite the opposite effect — but because pitching is to be his principal function on the team.
(6) The intention is to strengthen the body in general, and when the members sit down on the floor with their legs outstretched and practice touching their fingers to their toes, it is not because they hope to become galley slaves, perhaps the only occupation where that particular exercise would be relevant.
In general, relevancy is a facet of training rather than of education. What is taught at law school is the present law of the land, not the Napoleonic Code or even the archaic laws that have been scratched from the statute books. And at medical school, too, it is modern medical practice that is taught, that which is relevant to conditions today. (7)
In the liberal arts college, on the other hand, the student is encouraged to explore new fields and old fields, to wander down the bypaths of knowledge. (8)

A. At the Y gym, exercises have no such relevance.
B. There the teaching is concerned with major principles, and its purpose is to change the student, to make him something different from what he was before, just as the purpose of the Y gym is to make a fat man into a thin one, or a p one out of a weak one.
C. And the plumber and the carpenter and the electrician and the mason learn only what is relevant to the practice of their respective trades in this day with tools and materials that are presently available and that conform to the building code.
D. Training supplies the immediate and specific needs of society so that the work of the world may continue.
E. And in the other, he is training only to improve his own body and musculature.
F. The exercise would stop if the rules were changed so that sliding to a base was made illegal.
G. They are our intellectual leaders, the critics of our culture, the defenders of our free traditions, the instigators of our progress.
H. They may occupy positions of power and prestige, or they may be engaged in some humble employment.

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