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ding English books in the at that school have to study Maths, English, and science, but can d______ some subjects, I was very lucky to experience the different way of life and I really hope that someday I can go back and study in Manchester I always feel tired of so many classes and endless homework every day, so how I wish I could have fewer lessons and less homework to do!How I wish I could spend an hour each day taking part in the afterschool activities that I am fond of!How I wish I could drop some subjects I39。I hope that there is a beautiful lake with lots of trees under which I can listen to music or chat with my best friends。I have a dream that students can help each other and learn from each other。二.命題走向函數(shù)與方程的理論是高中新課標教材中新增的知識點,特別是“二分法”求方程的近似解也一定會是高考的考點。高考試題中有近一半的試題與這三個“二次”問題有關(guān)。(1)題型可為選擇、填空和解答;(2)高考試題中可能出現(xiàn)復(fù)合了函數(shù)性質(zhì)與函數(shù)零點的綜合題,同時考察函數(shù)方程的思想。D),把使f(x)=0成立的實數(shù)x叫做函數(shù)y=f(x)(x206。函數(shù)零點的意義:函數(shù)y=f(x)的零點就是方程f(x)=0實數(shù)根,亦即函數(shù)y=f(x)的圖象與x軸交點的橫坐標。函數(shù)y=f(x)的圖象與x軸有交點219。二次函數(shù)y=ax+bx+c(a185。零點存在性定理:如果函數(shù)y=f(x)在區(qū)間[a,b]上的圖象是連續(xù)不斷的一條曲線,并2222且有f(a)f(b)0,那么函數(shù)y=f(x)在區(qū)間(a,b)內(nèi)有零點。(a,b),使得f(c)=0,這個c也就是方程的根。f(b)0的函數(shù)y=f(x),通過不斷地把函數(shù)f(x)的零點所在的區(qū)間一分為二,使區(qū)間的兩個端點逐步逼近零點,進而得到零點近似值的方法叫做二分法.給定精度e,用二分法求函數(shù)f(x)的零點近似值的步驟如下:(1)確定區(qū)間[a,b],驗證f(a)f(x1)即若|ab|e,則得到零點零點值a(或b);否則重復(fù)步驟2~4。注:用二分法求函數(shù)的變號零點:二分法的條件f(a)3.二次函數(shù)的基本性質(zhì)(1)二次函數(shù)的三種表示法:y=ax2+bx+c;y=a(x-x1)(x-x2);y=a(x-x0)2+n。若-b2ab2ab2a若p≤-b2a)=m,f(q)=M;b2a若x0≤-若-b2a≥q,則f(p)=M,f(q)=m。①方程f(x)=0的兩根中一根比r大,另一根比r小219。f(r)236。239。237。239。236。b239。p③二次方程f(x)=0在區(qū)間(p,q)內(nèi)有兩根219。 2a239。239。af(p)0。f(p)[1,8](2)f(x)=log2(x+2)x,x206。[1,8]上零點的個數(shù) 小結(jié):函數(shù)零點的判定方法(1)解方程(2)用零點存在性定理。1)有兩個零點,則實數(shù)a的x232取值范圍是.2例3.(06浙江16)設(shè)f(x)=3ax+2bx++b+c=0,f(0)>0,f(1)>0,求證:ab(Ⅰ)a>0且2<<1;(Ⅱ)方程f(x)=0在(0,1):(I)因為f(0)0,f(1)0,所以c0,3a+2b+c+b+c=0,消去b,得 ac0;由條件a+b+c=0,消去c,得 a+b0,2a+bba1.(II)拋物線f(x)=3ax+2bx+c的頂點坐標為(在213b3aba1的兩邊乘以23132b3a,3acb3a2),得.又因為f(0)0,f(1)0,b3aa+cac3a22而f()=0,b3ab3a所以方程f(x)=0在區(qū)間(0,)與(,1)內(nèi)分別有一實根。第三篇:高三英語第一輪復(fù)習反思高三英語第一輪英語復(fù)習的教學反思李永強高三英語第一輪復(fù)習已經(jīng)結(jié)束,結(jié)合第二輪復(fù)習的開始,我就第一輪復(fù)習做以下反思:,讓同學們對老師的教學程序有個全面的了解?,F(xiàn)在看來,這個做法是非常有用,不但讓老師做的有的放矢,也讓學生做的井然有序。其中,最關(guān)鍵的部分是第一階段即基礎(chǔ)復(fù)習階段,它是學生們提高高考英語成績的保障,在這一階段教師要像拉網(wǎng)一樣,帶領(lǐng)學生們系統(tǒng)地、全面地復(fù)習所學的知識,同時注意查漏、補缺,統(tǒng)籌知識的連貫性。在要求學生記憶單詞時,我想了很多辦法,