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问题 填空题
设双曲线x2-y2=1的两条渐近线与直线x=
2
2
围成的三角形区域（包含边界）为D，点P（x，y）为D内的一个动点，则目标函数z=x-2y的最小值为______．
答案

双曲线x2-y2=1的两条渐近线是y=±x，解方程组

y=x
x=
2
2
，
y=-x
x=
2
2
，，
y=x
y=-x
得到三角形区域的顶点坐标是A(
2
2
，
2
2
)，B(
2
2
，-
2
2
)，C（0，0）．∴zA=
2
2
-2×
2
2
=-
2
2
，zB=
2
2
-2× (-
2
2
)=
3
2
2
，zC=0．

∴目标函数z=x-2y的最小值为-

2
2
．

答案：-

2
2
．

阅读理解

阅读理解。

Dear Grandma,

     I've been in Bluelake for two months now. It's a beautiful small city. Schools here begin at the end

of August. I like my school and I'm having a great time teaching Art History here.

     I'm now living in an apartment with a friend. From the window of my bedroom, I can see a beautiful

green hill with flowers and trees. Many people go there to have a picnic or to fly kites. I enjoy taking a

walk there every day after work and watching the people. 

    I miss you very much, Grandma, and I hope you can come and visit me here some day.

                                                                                                                              Love,

                                                                                                                              Jude

1. What is Bluelake?

A. A city.

B. A park.

C. A school.

D. An art museum.

2. What is Jude doing in Bluelake?

A. Working.

B. Studying.

C. Visiting a friend.

D. Taking a vacation.

3. Which picture best shows what Jude sees out of his bedroom window?

         A                     B                         C                          D
查看答案
单项选择题 A1/A2型题

学业性学习障碍不包括（）。

A.阅读缺陷

B.算术缺陷

C.拼字缺陷

D.构图缺陷

E.书写缺陷
查看答案