2. 关于
的不等式(![]()
-1)(
-2)>0,若此不等式的解集为{
|
<x<2},则
的取值范围是
A.
>0
B.0<
<2
C.
>
D.
<0
解析:由不等式的解集形式知m<0. 答案:D
考点2 含参数不等式的解法
题型1:解含参数有理不等式
例1:解关于
的一元二次不等式![]()
[解题思路]比较根的大小确定解集
解析:∵
,∴![]()
⑴当
,不等式解集为
;
⑵当
时,不等式为
,解集为
;
⑶当
,不等式解集为![]()
[名师指引]解含参数的有理不等式时分以下几种情况讨论:①根据二次项系数(大于0,小于0,等于0);②根据根的判别式讨论(
).③根据根的大小讨论(
).
题型2:解简单的指数不等式和对数不等式
例2. 解不等式loga(1-
)>1 ![]()
[解题思路]借助于单调性进行分类讨论
解析(1)当a>1时,原不等式等价于不等式组![]()
由此得1-a>
.因为1-a<0,所以x<0,∴
<x<0.
(2)当0<a<1时,原不等式等价于不等式组:
由 ①得x>1或x<0,由②得0
<x<
,∴1<x<
.
综上,当a>1时,不等式的解集是{x|
<x<0
,当0<a<1时,不等式的解集为{x|1<x<
}.
[名师指引]解指数不等式与对数不等式通常是由指数函数和对数函数的单调性转化为一般的不等式(组)来求解,当底数含参数时要进行分类讨论.
[新题导练]
1.不等式(
-2)
2+2(
-2) -4<0,对一切
∈R恒成立,则a的取值范围是( )
A.(-∞,2] B.(-2,2] C.(-2,2) D.(-∞,2)
解析:∵
可推知-2<a<2,另a=2时,原式化为-4<0,恒成立,∴-2<a≤2. 选B
2. 词数不少于120(不包括文章的开头)。
For thousands of years, people have accepted challenges in different fields.
1. 适当展开想象,语意连贯,结构完整。
84. If you are asked to describe the rise in home sales in February, which word do you think is the most appropriate? (No more than 1 word)
SECTION C
Directions: Write an English composition according to the instructions given below in Chinese
人们在生活中面临各种各样的挑战,请说一说人们为什么喜欢挑战和有哪些新的挑战有待人们探索。
注意:
83. What could be a surprise according to Monday’s report? (No more than 10 words)
82. Who is chief economist for the National Association of Realtors? (No more than 2 words)
●Women should not rush to drink alcohol to lose weight.
●For women with weight problems, alcoholic drinks are probably not the 80 of extra calories.
SECTION B
Directions: Read the following passage. Answer the questions according to the information given in the passage and the required words limit. Write your answers on your answer sheet.
The unsteady housing market is showing a rare sign of strength: waiting home sales were up significantly in February, a report released Monday said, suggesting that Americans took advantage of a tax credit for home buyers.
Sales rose 8.2 percent in February, the National Association of Realtors(房地产经纪人) said. Analysts had expected sales to stay flat.
Economists said Monday’s data suggested buyers were re-entering the market as the April 30 deadline approached for a government tax credit of up to $8,000. The tax credit drove up sales rapidly in the fall, when it was originally set to end, but it has been slow to push the market this spring.
Lawrence Yun, chief economist for the association, said Monday’s report “may signal the early stages of a second wave of home sales.”
A separate report on Monday showed the service division in the United States was improving, driven in part by gains in employment.
The Institute for Supply Management’s non-manufacturing barometer(晴雨表) rose to 55.4 in March, up from 53 in February, going beyond expectations. Much of the energy came from a rush in new orders and business activity.
It was the highest reading(测量或调查的读数) for the survey since May 2006. While employment rose, it was short of the break-even point, signaling the service division was still losing jobs. Exports also rose significantly.
“This is a very encouraging report, which indicates acceleration in demand growth from both domestic and foreign customers,” Barclays Capital researchers wrote in a note on Monday.
The jump in waiting home sales was a rare bit of good news for the housing market, which remains in a deep rut(车辙). Home prices have shown little change.
Analysts expect the housing market to gradually improve as unemployment becomes less and the broader recovery gains steam. But so far, relief has been slow to come.
Monday’s report showed sales rose even in areas hit hard by poor weather in February. Sales climbed 9 percent in the Northeast and South, which were blanketed by snow in February.
The Realtors association bases its data on signed contracts, which usually take one or two months to translate into final sales.
81. What is the effect of the government tax credit? (No more than 5 words)
Mild drinking may 79 to better heart health, but it also increases breast cancer risk.
● 41 percent becoming overweight or fat;
●nondrinkers gaining more weight over time, 9 pounds on average;
● 75 gaining about three pounds on average;
●compared with nondrinkers, women who consumed one or two alcohol drinks a day almost 30 percent 76 to become fat;
●women being 77 men in metabolism
湖北省互联网违法和不良信息举报平台 | 网上有害信息举报专区 | 电信诈骗举报专区 | 涉历史虚无主义有害信息举报专区 | 涉企侵权举报专区
违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com