问题 问答题

设二次型

为二次型的矩阵A的特征向量.

求正交变换x=QY,使二次型XTAX化为标准形.

答案

参考答案:

[*]

阅读理解

One day, while a woodcutter was cutting a branch of a tree above a river. When he began crying, God appeared and asked him, "Why are you crying?"

The woodcutter told him that he had dropped his axe into water. God went down into the water and reappeared with a golden axe.

"Is this your axe?" God asked.

The woodcutter said "No."

God again went down and came up with a silver axe." Is this your axe?" God asked.

The woodcutter said "No."

God again went down and came up with a iron axe." Is this your axe?" God asked.

The woodcutter said "Yes."

God was pleased with the man's honesty and gave him all the three axes.

The woodcutter went home happily. One day while he was walking with his wife along the river, his wife fell into the river. W hen he began crying, God appeared and asked him, "Why are you crying?"

"My wife has fallen into water."

God went down into the water and came up with Jennifer Lopez.

"Is this your wife?" God asked him.

"Yes." he said.

God was furious(狂怒的),"YOU CHEAT !Now I am going to curse you."

The woodcutter quickly said, “Forgive me my lord. It is a misunderstanding. IF I say 'No' to Jennifer Lopez, you will come up with Catherine Zeta Jones, If I also say 'No' to her, you will finally come up

With my wife and I will say, 'Yes.' Then you will give all the three to me .I am a poor man .I will not be able to look after all the three. So that's why I've to say 'Yes' "

小题1:Which of the following best describes the author's tone in telling the story?

A.Optimistic

B.Humoristic

C.Objective

D.Critical小题2:The impression that the woodcutter makes on you is that he is -----

A.foolish but honest

B.foolish and honest

C.smart but honest

D.smart and honest小题3:What can you infer about Jennifer Lopez and Catherine Zeta Jones?

A.They are the secret lovers of the woodcutter

B.They look much like the woodcutter's wife.

C.They are both rich women with a lot of gold and silver.

D.They are both popular with women, much worthy than his wife

单项选择题