中考数学复习专题一、实数及其运算

为搞好山东省交通科学研究所研发基地项目的结算审计工作,我跟踪审计部特针对本项目作如下要求,请各施工单位、供货单位遵照执行：andperformancetestcopiesoftherecord.Ifnecessary,reviewshouldbecarriedout;4)forspringhangers(includedsimplespring,hangersandconstantsupporthangers)itshouldalsoberecognizedassettingandlockingofloads.5)checkthesurfacequality,foldedlayeringandwithoutcracks,rustandotherdefects.5)aftercompletionofthetestandcontroldrawingnumberonebyone,byseriesbaled.Coloralloysteelparts,thepartsmarkinginstallationlocationandrotationaboutthedirectionyouwant.7.3.14.hangersinstallation7.3.14.1hangerlayouta.acleardesignofhangershouldbeinstalledstrictlyinaccordancewiththedrawingsanddesignsshallnotbeinstalledwrong,missing,etc.B.ownarrangementofpipingsupportandhangersetandselectionshouldbebasedoncomprehensiveanalysisofgenerallayoutofpipingsystems;coldinstallationofsteampipewithparticularattentionreservedforcompensationofthermalexpansiondisplacementandorientation.C.supportsystemsshouldberationaltowithstandpipeloads,staticloadandincidentalload;reasonablepipingdisplacement;guaranteedundervariousconditions,stressarewithintheallowedrange.Strength,stiffness,andmeetrequirementstopreventvibrationandsoothingwater,withoutaffectingtheadjacentequipmentmaintenanceandotherpipinginstallationandexpansion.D.equipmentconnectedtotheinterfacetomeetpipelinethrust(torque)limitrequirements;increasethestabilityofpipingsystemstopreventpipeline...Tubewallthickness(mm)2-34-67-10weldformnoslopemouthweldstrengtheningheighth(mm)1-1.51.5-2weldwidthb(mm)5-67-6hasslopemouthweldstrengtheningheighth(mm)1.5-22weldwidthb(mm)coverhadeachedgeslopemouthabout2mmargonarcweldingweldstrengtheningsurfaceheightandwidthtubewallthickness(mm)2--33--45--6weldformweldstrengtheningheighth(mm)1-1.51.5-22-2.5widthb(mm)第一章实数及其运算（宋体三号字加粗，居中）【知识要点】（宋体小四号字加粗）1、实数的分类：（宋体五号字）数）无理数（无限不循环小负分数正分数分数负整数零正整数整数有理数实数注意：可以化成分数的数都为有理数，有限小数和无限循环小数都可以化成分数。2、数轴三要素：原点、单位长度、正方向。3、相反数、绝对值：实数a的相反数是a；正数的绝对值是它本身，0的绝对值是0，负数的绝对值是它的相反数，即：)0()0(0)0(aaaaaa4、平方根：若2(0)xaa，则x叫做a的平方根。正数有两个互为相反数的平方根；0的平方根是0；负数没有平方根。正数a的正的平方根叫做a的算术平方根。5、立方根：若3xa，则x叫做a的立方根。每个实数都有且只有一个立方根。6、实数的大小比较：两个正数比较，绝对值大的数较大；两个负数比较，绝对值大的数反而小；正数＞0＞负数。注意：①数轴上右边的点对应的实数大于数轴上左边的点对应的实数。②能用有理数估计一个无理数的大致范围。7、二次根式：形如)0(aa的式子叫二次根式。8、实数的运算加法：同号两数相加，绝对值相加，符号不变；异号两数相加，较大绝对值的减去较小绝对值，符号同绝对值大的数的符号；（简记为：同号相加，符号不变；异号相减，符号从大）一个实数加0，就等于这个数。减法：减去一个数等于加上这个数的相反数。乘法：同号得正/异号得负，并把绝对值相乘；0乘任何数等于0。除法：除以一个数等于乘上这个数的倒数（0不能作除数）。乘方：annaaaa个；0正整数正有理数正数正分数正无理数实数负整数负有理数负数负分数负无理数为搞好山东省交通科学研究所研发基地项目的结算审计工作,我跟踪审计部特针对本项目作如下要求,请各施工单位、供货单位遵照执行：andperformancetestcopiesoftherecord.Ifnecessary,reviewshouldbecarriedout;4)forspringhangers(includedsimplespring,hangersandconstantsupporthangers)itshouldalsoberecognizedassettingandlockingofloads.5)checkthesurfacequality,foldedlayeringandwithoutcracks,rustandotherdefects.5)aftercompletionofthetestandcontroldrawingnumberonebyone,byseriesbaled.Coloralloysteelparts,thepartsmarkinginstallationlocationandrotationaboutthedirectionyouwant.7.3.14.hangersinstallation7.3.14.1hangerlayouta.acleardesignofhangershouldbeinstalledstrictlyinaccordancewiththedrawingsanddesignsshallnotbeinstalledwrong,missing,etc.B.ownarrangementofpipingsupportandhangersetandselectionshouldbebasedoncomprehensiveanalysisofgenerallayoutofpipingsystems;coldinstallationofsteampipewithparticularattentionreservedforcompensationofthermalexpansiondisplacementandorientation.C.supportsystemsshouldberationaltowithstandpipeloads,staticloadandincidentalload;reasonablepipingdisplacement;guaranteedundervariousconditions,stressarewithintheallowedrange.Strength,stiffness,andmeetrequirementstopreventvibrationandsoothingwater,withoutaffectingtheadjacentequipmentmaintenanceandotherpipinginstallationandexpansion.D.equipmentconnectedtotheinterfacetomeetpipelinethrust(torque)limitrequirements;increasethestabilityofpipingsystemstopreventpipeline...Tubewallthickness(mm)2-34-67-10weldformnoslopemouthweldstrengtheningheighth(mm)1-1.51.5-2weldwidthb(mm)5-67-6hasslopemouthweldstrengtheningheighth(mm)1.5-22weldwidthb(mm)coverhadeachedgeslopemouthabout2mmargonarcweldingweldstrengtheningsurfaceheightandwidthtubewallthickness(mm)2--33--45--6weldformweldstrengtheningheighth(mm)1-1.51.5-22-2.5widthb(mm))0(1aaapp)0(10aa开平方：22(0)()(0)(0)aaaaaaaaa运算顺序：首先乘方开方，再乘除，最后加减；同级运算，先左后右。9、特殊三角函数值：【典型例题】例1、计算:0185cos451+42.例2、已知：实数a、b满足1|1|0ab，求20102011ab．【基础题】一、选择题1、下列计算正确的是（三字符）A.9132B.10aC.532xxxD.9632222、在3154,,0.666,cos45,,927中，无理数有（）A.1个B.2个C.3个D.4个角α30°45°60°正弦（sinα）212223余弦（cosα）232221正切（tanα）3313为搞好山东省交通科学研究所研发基地项目的结算审计工作,我跟踪审计部特针对本项目作如下要求,请各施工单位、供货单位遵照执行：andperformancetestcopiesoftherecord.Ifnecessary,reviewshouldbecarriedout;4)forspringhangers(includedsimplespring,hangersandconstantsupporthangers)itshouldalsoberecognizedassettingandlockingofloads.5)checkthesurfacequality,foldedlayeringandwithoutcracks,rustandotherdefects.5)aftercompletionofthetestandcontroldrawingnumberonebyone,byseriesbaled.Coloralloysteelparts,thepartsmarkinginstallationlocationandro