廣東省肇慶市九年級上學期數(shù)學期末考試試卷

第第頁共14頁Cx+1)x-3)=0,解；由J京方程.猖創(chuàng)計1=0或k-3=0□解:由原方程,鋁證明；甜X?ftJOC±CD,AE±CDr/.OCiiAE.；,iCAE=zACO’l*OA=OCr?^OAC="COr21—1、21—1、\ZEAC=ZOACr\A匚平力解：\pAB=6i-\0A=OB=3,RtiCKD中”QC=OB=3,OD=3+2^5.由勾得CDm4,■-otiiAF■CE_CJsri'忑I~OD'即21—2、證明；?v^R^B^zPBA=lSOa-zAPB=60°r^P&C+^PBA=zABC=&Ocr；^FAB=zPBC.^/zAPe=^BPC=12Dfl.E薛：対溟?/■iABE^ACD都為尊邊三痢形.?^EAE=zCAD=6aD,AE=AB,AC-ADr"ME尢之CAD+AAC「?zEaC=zBAD”a-ACEE薛：対溟?/■iABE^ACD都為尊邊三痢形.?^EAE=zCAD=6aD,AE=AB,AC-ADr"ME尢之CAD+AAC「?zEaC=zBAD”a-ACE和」ABD中r;>ACE^ABDCSAS)h②證開!'.--ADF^-CFPr,.AF-PF=DF<F,VzAFP=^CFDrmAFP—CDF*,.^APF=^AC[>=W,「.zAPC=zCPD+zAPF-120"P,^EPC=120\/^APB=36D°--^APC=120fl,\AC=AD二￡BAD「22—2、「?再畫為-ABC■暗號盤.ifo解:直縷陽與相切?證明知下：融0D?vOA=ODr,=?又.vCBD=^,azCBD=^ODA?是!30的鳩■BC±ADP.\zC=90°r.-^CBD+z匚DE》勺(TP/.zQDA+zCDB=,.\zODB=90",;.BD丄OD.V'.'ODS^gr/.ED解;30",(^DOB=6(r.=61.'.OD=6?.又由(1)(和丄ODB=90°r/30=12*「*BD=^OB~~O￡^=^02?5Z>=^6^6^323—2、23—2、/眄毎三$心她-晞癱3百=18^3解;.^ACB=90Q.zA=28°^B=62B\ED=DC24_1、.nBCDfBDC=5臚,.^AOW-zBCD-Sr證明四邊飛EF醫(yī)呈正方形r江G二匚EtzGCE=zGFE=zFEC=90ft^ACB=zGCE=90Jrt\zGCB=zECA,'■GC=CE」CB=CAt25—i<-CAE^<BG.解:/CB=CA,CD-lABfzACB=900’;XD=BD=AD=2.zCBA=i：A=45ar丁丄匚AE^CBG..\zCBG=^A=45",.\zGBA=^GEC+zCBA=90n,■■zeEN+^BhJE^^O0』zBEN-^^CED=90a;^BNE=zCED「:z￡Bh=zCDE=9O*+,,NEE"ED匚rEDCD.y-2~r"T~~'心*3叫「■/-4?2521時，y的最大值為*一

K5解：枉CD上取一秋”鞭DE=&K=2近2K5解：枉CD上取一秋”鞭DE=&K=2近2.\ICC^EKr;^KEC=zKCE-225nr上匚EDW7F.,^FES=90i-675°=2