共查询到20条相似文献,搜索用时 62 毫秒
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<中学数学杂志>2001年第6期<曲线的运动与变换>一文中有一个结论是:"函数y=f(x)定义在R上,则函数y=f(ωx+A)与y=f(B-ωx)的图象关于直线x=B-A/2对称".我认为,函数y-f(ωx+A)与y=f(B-ωx)的图象关于直线x=B-A/2ω对称. 相似文献
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本文的f(x)是定义在A上的函数,对于任何一个x∈A,都有f(ωx+ψ)=f(x)(其中ω、ψ为常数).众所周知,在上式中当ω=1、ψ≠0时,f(x)是T=ψ的周期函数;当ω=-1时f(x)的图像关于直线x=-ψ/2对称;当ω=0时f(x)是常值函数y=f(ψ).那么,当ω≠±1、0时f(x)又是如何的函数呢? 相似文献
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陈晨 《数理天地(高中版)》2002,(2)
函数y=Asin(ωx+φ)是课本上研究的一个重点.高考命题时,也常以此函数为背景编制高考题,常见形式有下述几种: 1.单调性,单调区间例1 函数f(x)=Msin(ωx=φ)(ω>0)在区间[a,b]上是增函数,且f(a)=-M,f(b)=M,则函数g(x)=Mcos(ωx+φ)在[a,b]上( ) (A)是增函数. (B)是减函数. (C)可以取得最大值M. 相似文献
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常用于判别函数图象对称性的命题可归纳如下:命题1 若函数y=f(x)满足f(a x)=f(b-x),则y=f(x)的图象关于直线x=a b2对称.证 在y=f(x)图象上取A(a x0,y0),B(b-x0,y0),则AB中点为(a b2,y0),且对任一x0都成立,由x0任意性可知f(x)的图象关于直线x=a b2对称.推论1 若函数y=f(x)满足f(a ωx)=f(b-ωx),则y=f(ωx)关于x=12ω(a b)对称,即y=f(x)关于x=a b2对称.证 设ωx=t,则f(a t)=f(b-t),从而函数y=f(t)关于t=a b2对称,即y=f(ωx)关于直线x=a b2ω对称,或y=f(x)关于直线x=a b2对称.命题2 函数y=f(x)若满足f(a x)=-f(b-x),则y=f(x)的图象关于… 相似文献
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一、由繁到简,等价化归例1已知函数f(x)=2cos~2ωx+2sinωxcosωx+1(x缀R,ω>0)的最小正周期是π/2.(1)求ω的值.(2)求函数f(x)的最大值,并求使f(x)取得最大值的x的集合. 相似文献
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研究Hermite插值余项E(x)=f(x)-H(x)=m1!f(m)(ξ)ωm(x).在一定条件下估计‖f(m)(x)‖∞和‖ωm(x)‖∞的上界.提出一种在给定精度ε下计算f(x)的算法,同时给出数值实验. 相似文献
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《中学生数理化(高中版)》2016,(2)
<正>考点一:函数y=Asin(ωx+φ)的图像及变换例1设函数f(x)=sinωx+3(1/2)cosωx(ω>0)的周期为π。(1)求它的振幅、初相;(2)用五点法作出它在长度为一个周期的闭区间上的图像;(3)说明函数f(x)的图像可由y=sin x 相似文献
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郭红林 《唐山师范学院学报》1999,(5)
怎样确定可化为f(x)=Asinωx,f(x)=acosωx,f(x)=Atgωx,f(x)=Actgωx(其中A≠0,ω>0,x∈M R)的函数的周期,是学生们比较困惑的问题,对此笔者认为由周期函数的定义确定这类函数的周期,是值得重视的方法。 由周期函数定义域确定这类函数的周期,即根据现行教材中周期函数的定义“若存在非零常数T,使f(x T)=f(x)对定义域内的任意实数x都成立,则称f(x)是以T为周期的函数”中,以T为周期的函数f(x)的定义域M必定满足:“对任意的k∈Z,x kT与x同时在或同时不在M内,并且具有相同的形式”这一含义,布列含T的方程并求出T。 下面通过具体的例子说明。 相似文献
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一、应"优先"考虑特殊情况 例1 函数f(x)=Msin(ωx ψ)(ω>0)在区间[a,b]上是增函数且f(a)=-M,f(b)=M,则函数g(x)=Mcos(ωx ψ)在区间[a,b]上( ). 相似文献
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《海外英语》2007,(5):10-11
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? 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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《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
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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
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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
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献