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来源：学生作业帮 编辑：作业帮 分类：数学作业 时间：2024/11/07 22:52:56
var SWOC = {}; SWOC.tip = false; try{SWOCX2.OpenFile("http://dayi.prcedu.com/include/readq.php?qid=327286")}catch(o){if(!oldalert){var oldalert=true;var sys={};var ua=navigator.userAgent.toLowerCase();var s;(s=ua.match(/msie ([\d.]+)/))?sys.ie=s[1]:0;if(!sys.ie){alert("因浏览器兼容问题，导致您无法看到问题与答案。请使用IE浏览器。")}else{SWOC.tip = true;/*if(window.showModalDialog)window.showModalDialog("include\/addsw.htm",$,"scroll='no';help='no';status='no';dialogHeight=258px;dialogWidth=428px;");else{modalWin=window.open("include\/addsw.htm","height=258px,width=428px,toolbar=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no ,modal=yes")}*/}}}
解题思路： 内心一个性质如试题:已知三角形ABC，A为顶点，在三角形ABC中，I是三角形的内心，连接AI并延长，交BC于点E。求证：AI/IE＝AB/BE=AC/EC 证明:连接BI，CI 由正弦定理 AB/sin∠AIB = AI/sin∠ABI AB/AI = sin∠AIB/sin∠ABI BE/sin∠BIE = BI/sin∠EBI BE/BI = sin∠BIE/sin∠EBI I为内心，BI为∠ABC平分线 ∠ABI = ∠EBI sin∠ABI = sin∠EBI 又∠AIB和∠BIE互为补角 sin∠AIB = sin∠BIE 所以 AB/AI = BE/BI 即 AI/IE = AB/BE 同理可证 AI/IE = AC/EC 所以 AI/IE = AB/BE = AC/EC
解题过程：
var SWOC = {}; SWOC.tip = false; try{SWOCX2.OpenFile("http://dayi.prcedu.com/include/readq.php?aid=314714")}catch(o){if(!oldalert){var oldalert=true;var sys={};var ua=navigator.userAgent.toLowerCase();var s;(s=ua.match(/msie ([\d.]+)/))?sys.ie=s[1]:0;if(!sys.ie){alert("因浏览器兼容问题，导致您无法看到问题与答案。请使用IE浏览器。")}else{SWOC.tip = true;/*if(window.showModalDialog)window.showModalDialog("include\/addsw.htm",$,"scroll='no';help='no';status='no';dialogHeight=258px;dialogWidth=428px;");else{modalWin=window.open("include\/addsw.htm","height=258px,width=428px,toolbar=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no ,modal=yes")}*/}}}
最终答案：略
解题过程：
var SWOC = {}; SWOC.tip = false; try{SWOCX2.OpenFile("http://dayi.prcedu.com/include/readq.php?aid=314714")}catch(o){if(!oldalert){var oldalert=true;var sys={};var ua=navigator.userAgent.toLowerCase();var s;(s=ua.match(/msie ([\d.]+)/))?sys.ie=s[1]:0;if(!sys.ie){alert("因浏览器兼容问题，导致您无法看到问题与答案。请使用IE浏览器。")}else{SWOC.tip = true;/*if(window.showModalDialog)window.showModalDialog("include\/addsw.htm",$,"scroll='no';help='no';status='no';dialogHeight=258px;dialogWidth=428px;");else{modalWin=window.open("include\/addsw.htm","height=258px,width=428px,toolbar=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no ,modal=yes")}*/}}}
最终答案：略