题目

若函数f(x)=cosx+|sinx|(x∈［0,2π］)的图象与直线y=k有且仅有四个不同的交点,则k的取值范围是_______________. 答案：1≤k＜解:y=cosx+|sinx|=若直线y=k与f(x)的图象恰有4个不同交点,则y=k应与y=sin(x+),x∈［0,π］的图象恰有两个公共点,易得x∈［0,π］时,y∈［1,］.若sin(x+)=k有两个不同根,则有1≤k＜.It is the duty of every man to work. The life of a lazy man isn’t useful to himself and to others. If one is too lazy to work ,he will probably beg (乞讨) or steal (偷).So every boy, when he is young, should learn some useful work.But it is not enough that a boy should learn some kind of work. He should put all his heart into his work, and not waste his free time. “Work while you work and play while you play” is important for young people as for the old.The habit of getting up early is helpful to diligence(勤奋), and this, just like all other good habits, is most easily formed(形成) when one is young. There is an English saying “Lost time never returns.” This means that everybody must be diligent, and make use of (利用）his time. One must study hard when one is young so that one may make great progress, succeed(成功) in life and become useful to one’s country.  So we can say that diligence is the mother of success.【小题1】After reading the passage we know that those who are too lazy to work will become______.A．beggars B．thieves(小偷) C．beggars or thieves D．useful men 【小题2】If a boy wants to be useful to himself and to the people , he should ______.A．learn to play B．do something in his free time C．put his heart into his work D．try hard to learn to do a certain kind of work 【小题3】To learn to be diligent, it’s most important for the young people to______.A．make good use of time B．learn some good subjects C．work all the time without playing D．work while they work and play while they play 【小题4】One can’t be successful in life unless(除非) he ______ when he is young.A．is diligent in his study B．loves his school C．spends some time learning something D．makes up for his lost time 【小题5】Which of the following may be the best title for this passage?A．A Lazy Boy Can Learn To Be Diligent B．Young People Should Rise Early C．Lost Time Never Returns D．Diligence, the Mother Of Success