题目内容

【题目】已知函数f（x）是定义在R上的偶函数，当x≥0时，f（x）＝2x2－3x，则函数f（x）在R上的解析式是（ ）

A．f（x）＝－x（2x－3）

B．f（x）＝x（2|x|－3）

C．f（x）＝|x|（2x－3）

D．f（x）＝|x|（2|x|－3）

【答案】D

【解析】∵f（x）在R上是偶函数，且x≥0时，f（x）＝2x2－3x，

∴当x＜0时，－x＞0，f（－x）＝2（－x）2＋3x＝2x2＋3x，

则f（x）＝f（－x）＝2x2＋3x＝－x（－2x－3）．

又当x≥0时，f（x）＝2x2－3x＝x（2x－3），因此f（x）＝|x|（2|x|－3）．

练习册系列答案
相关题目

2017年4月，国家决定规划建设雄安新区，该区域地处保定城区与北京、天津之间，涉及河北省保定市的雄县、容城、安新3县及周边部分区域。下图为京津冀区域图。据此完成下列问题。

1.国家积极推进雄安新区建设的主要目的是

A. 加快我国城市化进程

B. 解决京津冀地区的雾霾问题

C. 分散北京的非首都职能

D. 逐步把新区建成我国新的行政中心

2.与保定城区相比，在雄县、容城、安新3县规划建设雄安新区的主要原因是

A. 交通便利 B. 开发程度低 C. 基础设施完善 D. 农业发达

【题目】Dear Liz,

My stay in Thailand has certainly been the experience of my life.

Life is busy and exciting. Bangkok is just like any other big city with a population of 10 million and heavy traffic. I’m very lucky because my host family is in a nice quiet area outside the city. There are Mr. and Mrs. Phairat, their son Sanan, who is 18, the daughter Chinda, who is 16, and Grandpa and Grandma.

I go to an international school with Sanan and Chinda. The school teaches about 70 percent in English, and 30 percent in Thai. I've learned some spoken language, but Thai writing is very difficult, The cooking lesson is my favourite. I'm learning all about Thai food and culture People don’t use chopsticks here, but spoons and forks. When I come back, I'm going to cook you a real Thai meal.

Last weekend we visited some temples. We also drove to Pattaya beach near Bangkok. I thought it was great, but Sanan and Chinda say that next month they’re taking me to Phuket Island, where the beaches are even more beautiful. The month after next, we’re going to travel to Mr. Phairat’s hometown in the north of Thailand. The Phairat’s own land there, and they have two elephants. I’m going to ride those elephants — and even wash them. Sanan and Chinda say it’s really fun.

I'm amazed by everything in this country, especially by the elephants. Elephants are an important part of Thai culture and way of life. They have been a traditional symbol of Thailand for many years in times of war and peace. In the seventh century, a Thai king trained 20, 000 elephants for battle.

I’ll tell you all about my Thai boxing lessons next time I write.

Love,

Mandy

【1】 How many family members are there in Mandy’s host family?

A. 4

B. 5

C. 6

D. 7

【2】 Next month, Mandy is going to visit__________.

A. Pattaya beach

B. Phuket Island

C. Phairat’s hometown

D. Bangkok

【3】 From the letter we know that Mandy is__________ when she stays in Thailand.

A. bored

B. quiet

C. excited

D. proud

【4】 What is the letter mainly about?

A. Study trip in Thailand

B. Food culture in Thailand

C. Elephant riding in Thailand

D. International schools in Thailand

【题目】设f（x）＝2x3，g（x）＝f（x+2），则g（x）等于（ ）

A．2x＋1 B．2x－1 C．2x－3 D．2x＋7

【题目】某超市将进货单价为10元的商品按12元一件的价格出售时，每天可销售80件，现在准备采用提高销售价格减少进货量的办法增加利润，已知这种商品每涨1元，其销售量就要减少10件，当该商品利润最大时，售价应定为________元.

【题目】

William Butler Yeats, a most famous Irish writer, was born in Dublin on June 13, 1865. His childhood lacked the harmony(和睦) that was typical of a happy family. Later, Yeats shocked his family by saying that he remembered “little of childhood but its pain”. In fact, he inherited(继承) excellent taste in art from his family—both his father and his brother were painters. But he finally settled on literature, particularly drama(戏剧) and poetry.

Yeats had strong faith in coming of new artistic movements. He set himself the fresh task in founding an Irish national theatre in the late 1890s. His early theatrical experiments, however, were not received favorably at the beginning. He didn’t lose heart, and finally enjoyed success in his poetical drama.

Compared with his dramatic works, Yeats’s poems attract much admiring notice. The subject matter includes love, nature, history, time and aging. Though Yeats generally relied on very traditional forms, he brought modern sensibility to them. As his literary life progressed, his poetry grew finer and richer, which led him to worldwide recognition.

He had not enjoyed a major public life since winning the Nobel Prize in 1923. Yet, he continued writing almost to the end of his life. Had Yeats stopped writing at age 40, he would who probably now be valued as a minor poet, for there is no other example in literary history of a poet who produces his greatest works between the ages of 50 and 75. After Yeats’s death in 1939, W.H.Auden wrote, among others, the following lines:

Earth, receive an honored guest:

William Yeats is laid to rest.

Let the Irish vessel(船) lie

Emptied of its poetry.

【1】 Which of the following can describe Yeats’s family?

A. It filled Yeats’s childhood with laughter.

B. It was shocked by Yeats’s choice.

C. It was a typically wealthy family.

D. It had an artistic atmosphere.

【2】According to the passage, what do we know about Yeats’s life?

A. Yeats founded the first Irish theater.

B. Yeats stuck to modern forms in his poetry.

C. Yeats began to produce his best works from the 1910s.

D. Yeats was not favored by the public until the 1923 Noble Prize.

【3】 What kind of feeling is expressed in W. H. Auden’s lines?

A. Envy.

B. Sympathy.

C. Emptiness.

D. Admiration.

【题目】下列函数中是幂函数的是（ ）

①y＝x2；②y＝2x；③y＝xπ；④y＝(x1)3；⑤y＝；⑥y＝x2＋.

A．①③⑤ B．①②⑤ C．③⑤ D．只有⑤

【题目】使用下面的词语写一段文字，要求主题鲜明，语言生动，80字左右。

屈原 端午节 晚会

答：

【题目】阅读下面的文言文，然后回答问题。

（甲）壬戌之秋，七月既望，苏子与客泛舟，游于赤壁之下。清风徐来，水波不兴。举酒属客，诵明月之诗，歌窈窕之章。少焉，月出于东山之上，徘徊于斗牛之间。白露横江，水光接天。纵一苇之所如，凌万顷之茫然。浩浩乎如冯虚御风，而不知其所止；飘飘乎如遗世独立，羽化而登仙。

…………

苏子曰：“客亦知夫水与月乎？逝者如斯，而未尝往也；盈虚者如彼，而卒莫消长也。盖将自其变者而观之，则天地曾不能以一瞬；自其不变者而观之，则物与我皆无尽也，而又何羡乎！且夫天地之间，物各有主，苟非吾之所有，虽一毫而莫取。惟江上之清风，与山间之明月，耳得之而为声，目遇之而成色，取之无禁，用之不竭，是造物者之无尽藏也，而吾与子之所共适。”

客喜而笑，洗盏更酌。肴核既尽，杯盘狼籍。相与枕藉乎舟中，不知东方之既白。

（节选自苏轼《赤壁赋》）

（乙）于是携酒与鱼，复游于赤壁之下。江流有声，断岸千尺。山高月小，水落石出。曾日月之几何，而江山不可复识矣。予乃摄衣而上，履巉岩，披蒙茸，踞虎豹，登虬龙，攀栖鹘之危巢，俯冯夷之幽宫。盖二客不能从焉。划然长啸，草木震动，山鸣谷应，风起水涌。予亦悄然而悲，肃然而恐，凛乎其不可留也。反而登舟，放乎中流，听其所止而休焉。时夜将半，四顾寂寥。适有孤鹤，横江东来。翅如车轮，玄裳缟衣，戛然长鸣，掠予舟而西也。

须臾客去予亦就睡梦一道士羽衣蹁跹过临皋之下揖予而言曰赤壁之游乐乎？问其姓名，俯而不答。“呜呼！噫嘻！我知之矣。畴昔之夜，飞鸣而过我者，非子也邪？”道士顾笑，予亦惊寤。开户视之，不见其处。

（节选自苏轼《后赤壁赋》）

【1】对下列句子中加横线词语的解释，不正确的一项是（ ）

A．而卒莫消长也 卒：到底

B．洗盏更酌 更：重新

C．履巉岩，披蒙茸 披：拨开

D．掠予舟而西也 西：向西

【2】下列各组句子中，加横线词的意义和用法相同的一组是（ ）

A．逝者如斯，而未尝往也 予乃摄衣而上

B．不知东方之既白 攀栖鹘之危巢

C．飘飘乎如遗世独立 凛乎其不可留也

D．于是携酒与鱼 却与小姑别，泪落连珠子

【3】下列对文章的理解与分析，不正确的一项是（ ）

A．甲文“客亦知夫水与月乎”一句在结构上承上启下，紧扣“水”与“月”，以答客的方式，展开了富有哲理的议论。

B．甲文中苏轼认为，无论宇宙还是人生，变与不变都是相对的，皆有短暂与永恒的两面，人对天地万物不必“羡其无穷”。

C．乙文中“山高月小，水落石出”的动态美，与甲文中“清风徐来，水波不兴”的静态美，展现了赤壁景物的多姿多态。

D．乙文道士化鹤的故事与“羽化而登仙”的道教思想有关，作者借此寄寓对超凡脱俗、自由自在境界的向往。

【4】把文中画横线的句子翻译成现代汉语。

（1）自其不变者而观之，则物与我皆无尽也，而又何羡乎！

（2）畴昔之夜，飞鸣而过我者，非子也邪？

【5】请用斜线（／）给文中画波浪线的部分断句。

须臾客去予亦就睡梦一道士羽衣蹁跹过临皋之下揖予而言曰赤壁之游乐乎？

违法和不良信息举报电话：027-86699610 举报邮箱：58377363@163.com

精英家教网