题目

（08年天津南开区质检一文）（14分）设函数（∈R，且）。当时，取得极大值2。（1）用关于a的代数式分别表示b与c；（2）当时，求的极小值；（3）求的取值范围。 答案：解析：本小题考查导数的意义，多项式函数的导数，考查利用导数研究函数的极值等基础知识，考查运算能力及分类讨论的思想方法。解：（1），由已知可得：即     ∴ （4分）（2）当时，b=2，c=1（5分）令（6分）时，为减函数时，为增函数（8分）∴ 有极小值（9分）（3）由，则（11分）∴ 要使的极One day, Mr. Smith went to a dinner party. He was wearing very old clothes. He came into the room. But people in the room didn’t look at him. They didn’t ask him to sit at the table. He wasn’t happy. But he said nothing.?Mr. Smith went home quickly and put on （穿上） his best clothes. He went back to the party. Everyone in the room stood up and looked at him. They gave him good food to eat. Mr. Smith took off his coat, and put it on the food and said, “Eat, coat!” The other people were surprised and asked, “What are you doing? Why do you do that?” Mr. Smith answered, “I am asking my coat to eat food. When I wore old clothes, you didn’t look at me. You didn’t ask me to sit down. Now I am wearing these nice clothes. And you give me good food. Now I see, you give the food to my coat, not to me.”?1.One day, Mr. Smith went to__________.A. a birthday party B. a dinner party C. an English party D. a movie2.When he came into the room, the people didn’t look at him. Why?A. Because the people didn’t ask him to come.B. Because Mr. Smith wore old clothes.C. Because Mr. Smith didn’t say hello to them first.D. Because it was night, they didn’t see him.?3.Why did he go home quickly?A. Because he didn’t want to stay here.B. Because he went home for his best clothes.C. Because the people there asked him to leave.D. Because he didn’t like the food there.?4.What’s the meaning of “surprised”in Chinese?A. 高兴的 B. 不满的 C. 感到奇怪的 D. 生气的5.Which statement is right?A. A person in good clothes should eat good food.B. A good coat should eat good food.C. We can’t judge(判断)a man by his clothes.D. Mr. Smith is stupid(愚蠢的).