讲《圆锥曲线》试卷二评1925:1722yx三、解答题2max2)2(,42)1(:18pSpap182)2(,5)1(:1922yxe)2)(23()2(,1)1(:20xym12)2(,36)1(:21exyONM0)22(22axpax代入抛物线得:04)22(22apa224811||papABAB:18axyl:1)设直线解:(2pap24pa42pap综上得),()2(00 yxAB的中点坐标为设paxypaxxx00210,2则)(:paxpyAB的中垂线方程为)0,2(paNxyONM2222224811||pappapAB=又AB:18),()2(00 yxAB的中点坐标为设)0,2(paNpapadABN22|2|的距离为到直线ppapS2222212 )42(,222pappapp2max24pSpa时,当)(:paxpyAB的中垂线方程为:19y..F2F1OxPaPFPFPFPF2||||||2||12121且)解:( aPFaPF2||,4||2121PFPF 又222222214416,4||||caacPFPF即522ace1P2Pxyabe2,45)2(22渐近线为知:由离心率),(),2,(),2,(00222111yxPxxPxxP设494272121xxOPOP由0221 PPPP由3)2(2322121xxyxxx:19y..F2F1OxP1P2P494272121xxOPOP由0221 PPPP由3)2(2322121xxyxxx在双曲线上,点P19)2(49)2(22212221bxxaxx19)2(9)2(22212221422axxaxxab198221axx22 a18222yx双曲线方程为::20xyOP2FQ1F),0(1bB)设解:(45,90121BOFBFF即则2245sinsin11BOFmme1 mmmxLmF1:),0,()2(2),1(QymmQ设mPFPFmPFPF4||||12||||222121由2||||21PFPFmyP1||32||:||22PFQF又32||:||PQyymyQ)32(||:20xyOP2FQ1FmmxLmF1:),0,()2(2),1(QymmQ设myQ)32(||mmmmmmmykQPQ1)32(1||||32 32)(:)1(Pxmmmm又mmxP1||2 其中2 m)2)(32(:2xylPFxyO2FB1F:21)0(,1baxaby)双曲线渐近线为解:(60两渐近线夹角为22333baab,4又双曲线焦距为422ba1,322 ba解得:36,1322eyx离心率椭圆方程为:xyOP2FB1F:21A)(:)2(cxbayl设),(22cabcaPxabyl交于点:与bbaAAbabAAPA22/22/||||||2222/22||||||||babebabAAAFAPAF22222222cacaebabe22221eee3)2(2)2[(22ee1232212)||||(22max22APAFe时,当/A作业:试卷