实验巧搭台,探究更精彩——利用“GC”探究函数性质的教学实践与思考

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.     

函数与方程在高中数学中的运用

<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     

实验巧搭台，探究更精彩--利用“GC”探究函数性质的教学实践与思考

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。     

浅谈复合函数的单调性

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.     

函数与其导函数的联系及应用

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     

利用消去法解函数方程

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)     

心智，在一题多解中激活

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____.     

洞悉问题症结及时强调注意点

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。     

用整数函数构造数列

函数f(x)=[x],x∈R表示不超过x的最大整数部分.如果用特殊的式子去代替x,其值构成一些很有趣的数列,并且可以通过这些数列构造出新的数列来. 一、定理由函数     

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     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

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.     

浅谈移民问题

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.     

Sister Carrie, an Adherent of Desires

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.     

Improvement of one-cycle controller by use of proportional integral differential controller

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

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

胡主席在印度,我却在中国

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.