2024年数学高考大一轮复习第九章 §9.11　圆锥曲线中求值与证明问题

这是一份2024年数学高考大一轮复习第九章 §9.11　圆锥曲线中求值与证明问题，共4页。
§9.11　圆锥曲线中求值与证明问题题型一　求值问题例1 (2022·新高考全国Ⅰ)已知点A(2,1)在双曲线C：－＝1(a>1)上，直线l交C于P，Q两点，直线AP，AQ的斜率之和为0.(1)求l的斜率；(2)若tan∠PAQ＝2，求△PAQ的面积．________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________思维升华 求值问题即是根据条件列出对应的方程，通过解方程求解．跟踪训练1 在平面直角坐标系xOy中，已知椭圆C：＋＝1(a>b>0)过点，焦距与长轴之比为，A，B分别是椭圆C的上、下顶点，M是椭圆C上异于A，B的一点．(1)求椭圆C的方程；(2)若点P在直线x－y＋2＝0上，且＝3，求△PMA的面积；(3)过点M作斜率为1的直线分别交椭圆C于另一点N，交y轴于点D，且点D在线段OA上(不包括端点O，A)，直线NA与直线BM交于点P，求·的值．________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________题型二　证明问题例2 (2023·邵阳模拟)已知抛物线C的焦点F在x轴上，过F且垂直于x轴的直线交C于A(点A在第一象限)，B两点，且|AB|＝4.(1)求C的标准方程；(2)已知l为C的准线，过F的直线l1交C于M，N(M，N异于A，B)两点，证明：直线AM，BN和l相交于一点．________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________思维升华 圆锥曲线证明问题的类型及求解策略(1)圆锥曲线中的证明问题，主要有两类：一是证明点、直线、曲线等几何元素中的位置关系，如：某点在某直线上、某直线经过某个点、某两条直线平行或垂直等；二是证明直线与圆锥曲线中的一些数量关系(相等或不等)．(2)解决证明问题时，主要根据直线与圆锥曲线的性质、直线与圆锥曲线的位置关系等，通过相关性质的应用、代数式的恒等变形以及必要的数值计算等进行证明．跟踪训练2 (2022·宁德模拟)若A，B，C(0,1)，D四点中恰有三点在椭圆T：＋＝1(a>b>0)上．(1)求椭圆T的方程；(2)动直线y＝x＋t(t≠0)与椭圆交于E，F两点，EF的中点为M，连接OM(其中O为坐标原点)交椭圆于P，Q两点，证明：|ME|·|MF|＝|MP|·|MQ|.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________