過拋物線
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的焦點
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且傾斜角為
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的直線
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與拋物線在第一、四象限分別交于
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兩點,則
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等于( )
試題分析:如圖,過
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作準線的垂線,垂足分別為
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,過
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作
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于
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,由垂直及拋物線的定義可知
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,所以
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,所以
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,所以
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.
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
拋物線

的焦點均在

軸上,

的中心和

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
從每條曲線上取兩個點,將其坐標記錄于下表中:
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
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
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
以橢圓

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
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
,
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
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
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
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
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都在以
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
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
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
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
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
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
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、
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
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
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
的方程;
(Ⅱ)若

的中垂線交
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軸于點
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,求
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
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如圖,曲線
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與曲線
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相交于

、
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、

、

四個點.
⑴ 求

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⑵ 求四邊形

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
與
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已知橢圓

的離心率為
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,過右焦點
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且斜率為

的直線與
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相交于
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兩點.若
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,則
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( )
A.1 | B. | C. | D.2 |
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已知雙曲線

的左、右焦點分別為

,以
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為直徑的圓與雙曲線漸近線的一個交點為
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,則此雙曲線的方程為( )
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已知定點

,
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,

是圓

:
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上任意一點,點

關于點

的對稱點為

,線段

的中垂線與直線

相交于點
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,則點

的軌跡是
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