题干

给出下列命题:
(1)若函数f(x)=|x|,则f’(0)=0;
(2)若函数f(x)=2x2+1,图象上P(1,3)及邻近上点Q(1+Δx,3+Δy), 则
△
y
△
x
=4+2Δx
(3)加速度是动点位移函数S(t)对时间t的导数;
(4)y=2cosx+lgx,则y’=-2cosx·sinx+
1
x

其中正确的命题有(   )

A:0个

B:1个

C:2个

D:3个

上一题 下一题 0.0难度 选择题 更新时间:2014-08-05 05:37:49

答案(点此获取答案解析)

B

同类题1

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

How to Enjoy Life As a Teen

    The "best years of your life"? Maybe not, but you can learn to make the most of your high school days.

    Learn to appreciate small things. Whether it's having a computer, having friends, having a good supply of food, a bed to sleep on, family that loves you, having a decent education or simply being born in this world, value it. ____ Be happy, and life will reward you. Remember that these are the last few years you will be able to enjoy yourself without having to worry about the responsibility of an adult, but make sure you prepare yourself for when you do become one. When you actually become an adult, you'll learn to love that responsibility and you probably never want to go back.

    Choose your friends wisely. Unlike what many articles state, you don't have to be popular and have a gazillion friends to be happy. ____ Try to have friends that like you who you are, not just because you are wearing a certain brand of shoes or something like that. These are people who shop at the same store as you; not someone who will sympathize with you when your dog dies.

    Keep your grades up. ____ This also sets you up to get into a college you want to go to, which in turn prepares you for a career you will enjoy, improving your quality of life in the future. You'll get cheap car insurance as well if you have at least a B or A average.

    ____ Participating in clubs, activities, and sports increases your chances of meeting new friends. While you only need 4 or 5 close friends, that doesn't mean you shouldn't try to meet new people. Participating gives you something to do instead of sitting bored at home and wallowing in self-pity.

    Work at a job you can enjoy. Working is a great way co gain experience and to meet other people. ____ This will look great on your resume. If you can't find work, especially in this hard economic time, volunteer or make your own job.

A. Be sociable.

B. Remember the point of life is for you to enjoy it.

C. Find a hobby that is meaningful or practical.

D. In fact, many of the "friends" you have when you are popular are not true friends.

E. When you do get out of college, interviewing companies will look at your previous work experience.

F. Even though you want to enjoy your teen life as best as possible, don't idle away your time in school.

G. There is nothing more satisfying than seeing your hard work pay off in the form of A's and B's (but mainly A's).

同类题4

阅读下文,回答问题。

成功

季羡林

    什么叫成功?顺手拿来一本《现代汉语词典》,上面写道:“成功:获得预期的结果”,言简意赅,明白之至。

    但是,谈到“预期”,则错综复杂,纷纭混乱。人人每时每刻每日每月都有大小不同的预期,有的成功,有的失败,总之是无法界定,也无法分类,我们不去谈它。

    我在这里只谈成功,特别是成功之道。这又是一个极大的题目,我却只是小做。

    积七八十年之经验,我得到了下面这个公式:

    天资+勤奋+机遇=成功

    谈到天资,首先必须承认,人与人之间天资是不相同的,这是一个事实,谁也否

    定不掉。今天,学术界和文艺界自命天才的人颇不稀见,我除了羡慕这些人“自我感觉过分良好”外,不敢赞一词。对于自己的天资,我看,还是客观一点好,实事求是一点好。

    至于勤奋,一向为古人所赞扬。囊萤、映雪、悬梁、刺股等故事流传了千百年,家喻户晓。韩文公的“焚膏油以继晷(guǐ),恒兀兀以穷年”,更为读书人所向往。

    如果不勤奋,则天资再高也毫无用处。事理至明,无待饶舌。

    谈到机遇,往往为人所忽视。它其实是存在的,而且有时候影响极大。就以我自

    己为例,如果清华不派我到德国去留学,则我的一生完全不会像现在这个样子。

    把成功的三个条件拿来分析一下,天资是由“天”来决定的,我们无能为力。机遇是不期而来的,我们也无能为力。只有勤奋一项完全是我们自己决定的,我们必须在这一项上狠下功夫。在这里,古人的教导也多得很。韩文公说:“业精于勤荒于嬉,行成于思毁于随。”这两句话是大家都熟悉的。

    我认为,这三方面,是成功的必由之路。