初一初二数学公式整理

初一初二数学公式整理 初一、初二数学整理 【一次方程(组)与一次不等式(组)】 ?算术解法与代数解法 1、未知数和方程 ? 用字母x、y…等，表示所要求的数量，这些字母称为“未知数”。 ?用运算符号把数或表示书的字母联结而成的式子，叫做代数式。 ?含有未知数的等式，叫做方程，在一个方程中，所含未知数，又称为元; ?被“，”、“,”号隔开的每一部分称为一项在一项中，数字或表示已知数的字母因数叫做未知数的系数 ?某一项所含有的未知数的指数和，称为这一项的次数 ?不含未知数的项，称为常数项当常数不为零时，它的次数是0，因此常数项也称为零次项 2、方程的解与解方程的根据 ?能使方程左右两边的值相等的未知数的值，叫做方程的解，也叫做根 ?求方程解的过程，叫做解方程 ?解方程的根据是“运算通性”及“等式性质” ?可以“由表及里”地去掉括号，并将“含有相同未知数且含未知数的次数也相同”的各项结合起 来，合并在 一起——这叫做合并同类项 ?把方程一边的任一项改变符号后，移到方程的另一边，叫做移项简单说就是“移项变号” 把方程两边各同除以未知数的系数(或同乘以系数的倒数)，就得到未知数应取的值 综上所述，得到解方程的 方法 快递客服问题件处理详细方法山木方法pdf计算方法pdf华与华方法下载八字理论方法下载 、步骤: a、去括号 b、移项变号 bc、合并同类项，使方程化为最简形式ax=b(a?0)、除以未知数的系数，得出 (a?0) x,a ?一元一次方程 1、一元一次方程的概念 axb，,0只含有一个未知数并且次数是1的方程，叫做一元一次方程。 一般形式: (a?0，a、b是常数) 2、一元一次方程的解法 解一元一次方程的一般步骤是: of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury, is strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the storage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when scrolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at the scene, checks should be carried out promptly, the technical documentation of the products should be complete, cable length should conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4.1.2.1.3 cable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water. 4.1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and significant depressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical damage and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, the tube free of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, the degree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius should not be less than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter and outer diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and length of the steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the design and the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the support a、去分母(或化为整系数); b、去括号; c、移项变号; axb,, d、合并同类项，化为 (a?0)的形式; b e、方程两边同除以未知数的系数，得出方程的解 (a?0) x,,a 【一元二次方程】 ?平方与平方根 1、平方根 a、正数有两个平方根，这两个平方根互为相反数; b、零只有一个平方根，它就是零本身; c、负数没有平方根 2、实数 无限不循环小数叫做无理数;有理数和无理数统称为实数 ?平方根的运算 1、算术平方根的性质 性质1:一个非负数的算术平方根的平方等于这个数本身 性质2:一个数的平方的算术平方根等于这个数的绝对值 2、算术平方根的乘、除运算 a、算术平方根的乘法 ababab,, ,,(0,0) aa, ,,(0,0)ab b、算术平方根的除法注意最终结果分母不含根号。 bb 通过分子、分母同乘以一个式子把分母中的根号化去或把根号中的分母化去，叫做分母有理化 a、被开方数的每个因数的指数都小于2; b、被开方数不含有字母 我们把符合这两个条件的平方根叫做最简平方根 3、算术平方根的加、减运算 如果几个平方根化成最简平方根以后，被开方数相同，那么这几个平方根就叫做同类平方根 把几个同类二次根式合并为一个二次根式就叫做合并同类二次根式 二次根式加减时，可以先将二次根式化为最简二次根式，再将被开方数相同的进行合并。 d the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the supthe steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the design an th ofter diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and lengless than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter and ou ot beegree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius should nfree of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, the d e tubege and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, thpressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical damant de1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and significacable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water. 4. .2.1.3conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4.1, checks should be carried out promptly, the technical documentation of the products should be complete, cable length should scene rolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at thetorage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when scis strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the s of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury,2port 初一、二数据公司整理 ?一元二次方程及其解法 1、一元二次方程 只含有一个未知数，且未知数的最高次数是2的方程，叫做一元二次方程 2一元二次方程的一般形式:(，，是常数，?0) axbxc，，,0acab 2、一般的一元二次方程的解法 ,1，直接开平方法 用直接开平方法解一元二次方程的一般步骤是: 2a、化二次项系数为1 :用二次项系数去除方程两边，将方程化为的xkk，, ,0(0)形式 2xk,, b、移项:把常数项移至方程右边，将方程化为的形式 c、开方:方程两边同时开方，得到原一元二次方程的两根 xk,,,1,2 ,2，公式法 用公式法解一元二次方程的一般步骤是: 、b、c表示原一元二次方程的二次项系数、一次项系数、常数项 a、分别用a b、将二次项系数、一次项系数、常数项(即a、b、c)分别带入求根公式 2,,,bbac4x,， 2a 就能得到原一元二次方程的两根 ,3，配方法 用配方法解一元二次方程的一般步骤是: 2 a、化二次项系数为1 用二次项系数去除方程两边，将方程化为xpxq，，,0的形式 2 b、移项 把常数项移至方程右边，将方程化为xpxq，,,的形式 c、 配方 方程两边同时加上“一次项系数一半的平方”，是方程左边称为含有未知数的完 全平方形式，右边是一个常数 ,4，因式分解法 用因式分解法解一元二次方程的一般步骤是: a、将原一元二次方程进行因式分解，将方程化为a(x,p)(x,q)=0的形式 b、因为a?0，所以x,p=0或x,q=0 3tupporand the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the s of the steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the designmage and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, ngth outer diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and le be less than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter andd not e degree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius shoulbe free of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, ththe tudepressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical dacant 4.1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and signifi .3 cable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water..1.2.1d conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4ne, checks should be carried out promptly, the technical documentation of the products should be complete, cable length shoule scecrolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at thstorage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when s is strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury, c、得到原一元二次方程的两根x=p，x=q 12 3、一元二次方程的求根公式 2,,,bbac42当时， bac,,40x,2a 4、一元二次方程根的判别式 2 当Δ=b,4ac>0时，有两个不相等的实数根; 2 当Δ=b,4ac=0时，有两个相等的实数根; 2当Δ=b,4ac<0时，没有实数根 5、一元二次方程的根与系数的关系(韦达定理) 22若方程ax+bx+c=0的两根是x，x，那么原方程可以化为 axxxxxx[()]0,，，,,121212 bcxx,xx，,,，。 即1212aa 【多项式的四则运算】 ?单项式与多项式 1、单项式 仅含有一些数和字母的乘法(包括乘方)运算的式子叫做单项式。(单独的一个数或字母也是单项 式) 单项式中的数字因数叫做这个单项式(或字母因数)的数字系数，简称系数 当一个单项式的系数是1或-1时，“1”通常省略不写 一个单项式中，所有字母的指数的和叫做这个单项式的次数 如果在几个单项式中，不管它们的系数是不是相同，只要他们所含的字母相同，并且相同字母的 指数也分别相同，那么，这几个单项式就叫做同类单项式，简称同类项。所有的常数都是同 类项 2、多项式 由有限个单项式的代数和组成的式子，叫做多项式 多项式里每个单项式叫做多项式的项，不含字母的项，叫做常数项 单项式可以看作是多项式的特例 把同类单项式的系数相加或相减，而单项式中的字母的乘方指数不变 4portd the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the supthe steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the design an th ofter diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and lengless than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter and ou ot beegree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius should nfree of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, the d e tubege and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, thpressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical damant de1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and significacable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water. 4. .2.1.3conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4.1, checks should be carried out promptly, the technical documentation of the products should be complete, cable length should scene rolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at thetorage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when scis strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the s of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury, 初一、二数据公司整理 在多项式中，所含的不同未知数的个数，称做这个多项式的元数。经过合并同类项后，多项式所 含单项式的 个数，称为这个多项式的项数。所含单项式中最高次项的次数，就称为这个多项式的次数 ?多项式的加、减法，乘法 1、多项式的加、减法 一般的，几个整式相加减，如果有括号就先去括号，然后再合并同类项。 2、单项式的乘法 单项式相乘，用它们系数的积作为积的系数，对于相同的字母因式，则连同它的指数作为积的一 个因式 3、多项式的乘法 多项式与多项式相乘，先用一个多项式的每一项乘以另一个多项式的各项，再把所得的积相加 4、常用乘法公式 22 公式1 平方差公式: ()()ababab，,,, 222222 公式2 完全平方公式 ()2abaabb，,，，()2abaabb,,,， 5、式的除法 两个单项式相除，就是它们的系数、同底数的幂分别相除，而对于那些只在被除式里出现的字母， 连同它们的指数一起作为商的因式，对于只在除式里出现的字母，连同它们的指数的相反数 一起作为商的因式 一个多项式处以一个单项式，先把这个多项式的每一项除以这个单项式，再把所得的商相加。 【因式分解】 ?因式分解 1、因式 如果一个次数不低于一次的多项式因式，除这个多项式本身和非零常数外，再也没有其他的因式， 那么这个因式(即该多项式)就叫做质因式 2、因式分解 把一个多项式写成几个质因式乘积形式的变形过程叫做多项式的因式分解 a、提取公因式法 b、运用公式法 5of the steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the designtupporand the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the sngth outer diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and le be less than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter andd not e degree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius shoulbe free of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, ththe tumage and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, depressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical dacant 4.1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and signifi .3 cable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water..1.2.1d conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4ne, checks should be carried out promptly, the technical documentation of the products should be complete, cable length shoule scecrolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at thstorage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when s is strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury, c、分组分解法 d、十字相乘法 e、配方法 f、求根公式法 【分式与二次根式】 ?分式与分式方程 1、分式和分式的基本性质 A 形如，A、B是整式，B中含有未知数且B不等于0的整式叫做分式。 B 分式的基本性质 :分数的分子与分母都乘以或除以同一个不等于0的数，分数的值不变 2、分式的约分和通分 分式的约分是将分子与分母的公因式约去，使分式化简 分式化成同分母的分式，这一过程叫做通分。 将异分母的 3、分式的运算 乘除法法则: 两个分式相乘，把分子相乘的积作为积的分子，把分母相乘的积作为积的分母。 两个分式相除，把除式的分子和分母颠倒位置后再与被除式相乘。 加减法法则: 同分母的分式相加减，分母不变，把分子相加减。 异分母的分式相加减，先通分，化为同分母的分式，然后再按同分母分式的加减法法则进行计算。 4、分式方程 分式方程的意义:分母中含有未知数的方程叫做分式方程。 分式方程的解法:?去分母(方程两边同时乘以最简公分母,将分式方程化为整式方程); ?按解整式方程的步骤求出未知数的值; ?验根(求出未知数的值后必须验根，因为在把分式方程化为整式方程的过程 中，扩大了未知数的取值范围，可能产生增根)。 ?二次根式 1、根式 在实数范围内，如果n个x相乘等于a，n是大于1的整数，则称x为a的n次方根 portd the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the supthe steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the design an th ofter diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and lengless than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter and ou ot beegree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius should nfree of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, the d e tubege and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, thpressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical damant de1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and significacable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water. 4. .2.1.3conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4.1, checks should be carried out promptly, the technical documentation of the products should be complete, cable length should scene rolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at thetorage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when scis strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the s of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury,6 初一、二数据公司整理 含有数字与变元的加，减，乘，除，乘方，开方运算，并一定含有变元开方运算的算式称为无理式 2、一般地,形如a(a?0)的代数式叫做二次根式。当a?0时,a表示a的算术平方根。 3、最简二次根式与同类根式 具备下列条件的二次根式称为最简二次根式: a、被开方式的每一个因式的指数都小于开方次数 b、根号内不含有分母 如果几个二次根式化成最简根式以后，被开方式相同，那么这几个二次根式叫做同类根式 4、二次根式的运算 二次根式的乘除法: a、算术平方根的乘法a?b=ab(a?0，b?0) aa b、算术平方根的除法=(a?0，b?0)) 注意最终结果分母不含根号。 bb 二次根式的加减法: a、如果几个平方根化成最简平方根以后，被开方数相同，那么这几个平方根就叫做同类平方根 b、把几个同类二次根式合并为一个二次根式就叫做合并同类二次根式 c、二次根式加减时，可以先将二次根式化为最简二次根式，再将被开方数相同的进行合并。 d、非同类二次根式不能合并 5、无理方程 根号里含有未知数的方程叫做无理方程 【函数与图像】 ?数轴 1、有向直线 为了区别一条直线的两个不同方向，可以规定其中一方向为正向，另一方向为负向 规定了正方向的直线，叫做有向直线，读作有向直线l 2、数轴 ?规定了唯一的原点，唯一的正方向和唯一的单位长度的直线叫数轴。 ?所有的有理数都可以用数轴上的点来表示。也可以用数轴来比较两个实数的大小。 7of the steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the designtupporand the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the sngth outer diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and le be less than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter andd not e degree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius shoulbe free of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, ththe tumage and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, depressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical dacant 4.1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and signifi .3 cable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water..1.2.1d conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4ne, checks should be carried out promptly, the technical documentation of the products should be complete, cable length shoule scecrolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at thstorage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when s is strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury, ?我们把数轴上任意一点所对应的实数称为点的坐标 ?对于每一个坐标(实数)，在数轴上可以找到唯一的点与之对应这就是直线的坐标化 ?数轴上任意一条有向线段的数量等于它的终点坐标与起点坐标的差。任意一条有向线段的长度 等于它两个端 点坐标差的绝对值 ?平面直角坐标系 1、平面的直角坐标化 222、两点间的距离公式,AB=(x,x)+(y,y) ABAB 2变形:直线上任意两点之间的距离AB=|x,x|1+k AB x+x+yy12123、中点公式,x=，y= 22 ?函数 1、常量,变量和函数 在某一过程中可以取不同数值的量，叫做变量。在整个过程中保持统一数值的量或数，叫做常量 或常数 一般地，设在变化过程中有两个互相关联的变量x，y，如果对于x在某一范围内的每一个确定的 值，y都有 唯一确定的值与之对应，那么就称y是x的函数，x叫做自变量。 ?解析法 就是用等式来表示一个变量是另一个变量的函数，这个等式叫做函数的解析表达式 (函数关系式) ?列表法 ?图像法 2、函数的图像 知道函数的解析式，要画函数的图像，一般分为列表，描点，连线三个步骤 ?正比例函数 1、正比例函数 一般地，函数y=kx(k?0)叫做正比例函数。 正比例函数y=kx(k?0)有下列性质: a、当k>0时，它的图像经过第一，三象限，y随着x的增大而增大; 当k<0时，它的图像经过第二，四象限，y随着x的增大而减小， ge and buried at the larger force, sufficient strength of pipe should be used. 4.1.2.2.2 cable protection tube processing, thpressions, smooth inside walls should be, cable protection pipe may not have severe corrosion, susceptible to mechanical damant de1.2.2 of cable protection pipe processing and laying 4.1.2.2.1 cable protection pipe must be perforated, cracks and significacable should focus on the store, and shall identify the model, specification. Storage cables should be dry, without water. 4. .2.1.3conform to the drawings, specifications, requirements, attachments should be complete, cable termination should be tight. 4.1, checks should be carried out promptly, the technical documentation of the products should be complete, cable length should scene rolling arrows on the cable drum instructions or entangle the cable direction. And its annexes 4.1.2.1.2 cable arrived at thetorage; transport and the scroll cable disc Qian, must guarantee cable disc firm, cable around tight, and Must follow when scis strictly prohibited will cable disc directly by car Shang push Xia, cable disc not should flat put transport and the s of transport and the custody 4.1.2.1.1 cable in transport process in the not should makes cable and the cable disc by injury,8portd the physical path length of each cable, arrange each cable, reducing the cable connectors. 4.1.4.3 cable spacing of the supthe steel shaft should tie in with cable reel weight and width. Before laying should be calculated according to the design an th ofter diameter of the cable than not ... Hurt, well insulated. 4.1.4.2 cable lines should be placed securely, strength and lengless than the penetration of the minimum permissible bending radius of the cable. Cable protection pipe inner diameter and ou ot beegree of bend flat should not be bigger than the outside diameter of the pipe 10%; cable protection pipe bend radius should nfree of burrs and sharp edges and corners, and trumpet. Cable protection pipe after bending, there should be no cracks, the d e tube 初一、二数据公司整理 b、随着比例函数的绝对值的增加，函数图像渐渐离开x轴而接近于y轴，因此，比例系数 k和直线y=kx与x轴正方向所成的角有关。据此，k叫做直线y=kx的斜率。 2、反比例函数 k 一般地，函数y=(k?0)叫做反比例函数 x k 反比例函数y=(k?0)有下列性质: x a、当k>0时，它的图像的两个分支分别位于一、三象限内，在每一个象限内，y随x的增大而减 小; 当k<0时，它的图像的两个分支分别位于二、四象限内，在每一个象限内，y随x的增大而增 大 b、它的图像的两个分支都无限接近但永远不能达到x轴和y轴 ?一次函数及其图像 1、一次函数及其图像 如果k=0时，函数变形为y=b，无论x在其定义域内取何值，y都有唯一确定的值b与之对应， 这样的函数我们称它为常函数 直线y=kx+b与y轴交与点(0，b)，b叫做直线y=kx+b在y轴上的截距，简称纵截距 2、一次函数的性质 函数y=f(x)，在a