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1.
图形计算器作为数学学习的工具和移动的数学实验室,让我们可以用新的视角解读和解决数学问题.在探究函数f(x)=ax+b x性质的教学实践中,借助"GC"搭建平台,引导思考、自主探究、激活思维,感受新技术给数学教学带来的正能量,真正实现"玩转"数学课堂.  相似文献   

2.
<正>高中数学中,很多函数问题均要用到方程知识进行求解,而很多方程类的问题,也离不开函数知识的辅助。1.方程根、函数零点例1函数f(x)=2~x|log_(0.5)x|-1的零点个数是多少个?解题:要想求得f(x)=2~x|log_(0.5)x|-1零点个数,需要让f(x)=0,这样可以得到方  相似文献   

3.
图形计算器作为数学学习的工具和移动的数学实验室,让我们可以用新的视角解读和解决数学问题。在探究函数f(x)=ax+ bx 性质的教学实践中,借助“GC”搭建平台,引导思考、自主探究、激活思维,感受新技术给数学教学带来的正能量,真正实现“玩转”数学课堂。  相似文献   

4.
今年高考理工科数学试题,有这样一道题:“函数log_(0.5)(x~2 4x 4)在什么区间上是增函数?”有些考生根据“当对数的底在0与1之间时,对数函数是减函数”的性质,得出“函数log_(0.5)(x~2 4x 2)没有增函数区间”的结论.这个结论是错误的.我们可以从函数的单调性来研究这个函数的性质.  相似文献   

5.
高中课本中导函数定义:如果函数y=f(x)在开区间(a,b)内的每点处都有导数,此时对于每一个x∈(a,b),都对应着一个确定的导数f(′x),从而构成一个新的函数f(′x),称这个函数f(′x)为函数y=f(x)在开区间内的导函数.f(′x)=y′=limΔx→0ΔyΔx=limΔx→0f(x Δx)-f(x)Δx.那么函数y  相似文献   

6.
把函数中的x换成另一种形式,得到一个新的函数方程,联立新旧方程,求出函数解析式。例1如果f(x)满足af(x)+bf(1/x)=cx,其中a,b,c是非零常数,且a≠±b,求f(x)的表达式。解析在已知函数方程中用1/x代换x,得af(1/x)  相似文献   

7.
平时,我们竭尽全力地去探索一道题目的多种解法的真正目的是什么?开拓思路,训练思维,培养能力,激活心智!这"激活心智"确实是我们追求的最高境界.问题1 函数 y=(x 1)~(1/2)/(x 2)的值域是____.  相似文献   

8.
在教学的重点、关键之处,当学生答非所问时,教师应察其言,观其行,掌握学生的思维脉搏,洞悉问题症结之所在,尔后采取针对性的补救措施,及时强调注意点。 例如,在讲完函数概念后,有这样一道题:某种茶杯每个0.5元,买x个茶杯的钱数(元)f(x)=O.5x(x为正整数),画出这个函数的图象。  相似文献   

9.
数学科     
例一:已知幂函数图像过点M(2,1/4),则f(0.5)=( )(A)2~(1/2)/2 ;(B)1/4;(C)4;(D)2~(1/2)[评析]这道题考查了函数的基本概念,初等函数的解析表达式,当x=x_0时求函数值y_0=f(x_0),及待定系数法等重要内容.解答本题首先要清楚幂函数的解析式是y=x~n,其次对函数图像的概念:“设函数y=f(x)定义在数集A上,则坐标平面上的点集{(x,y)|x∈A,y=f(x)}称为函数y=f(x)的图像”有明确的认识.一般的函数图像过点M(x_0,y_0).可以理解为x=x_0时y=y_0由已知幂函数  相似文献   

10.
1问题导出例1(2012年高考福建卷·文22)已知函数f(x)=ax sin x-3/2(a∈R),且在[0,π/2]上的最大值为π-3/2(Ⅰ)求函数.f(x)的解析式;(Ⅱ)判断函数f(x)在(0,π)内的零点个数,并加以证明.本题通过基本素材x,sinx搭建考查平台,考点涉及零点,最值,单调性,解析式等基础知识,考查了导数在研究函数中的应用,考查函数与方程思  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
汉字倒说     
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。  相似文献   

13.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

14.
王菲 《华章》2007,(12):273-273
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.  相似文献   

15.
裴水妹 《华章》2007,(11):196
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.  相似文献   

16.
17.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

18.
钱生钱!     
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了  相似文献   

19.
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.  相似文献   

20.
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.  相似文献   

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