點
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是平面
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內(nèi)的定點,點
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與點
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不同)的“對偶點”
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是指:點
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在射線
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上且
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厘米
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.若平面
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內(nèi)不同四點
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在某不過點O的直線
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上,則它們相應(yīng)的“對偶點”
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在
A.一個過點 的圓上 | B.一個不過點 的圓上 |
C.一條過點 的直線上 | D.一條不過點 的直線上 |
試題分析:過
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作與直線
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垂直的直線
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以
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為原點,直線
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為
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軸,單位為
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厘米,建立平面直角平面坐標系. 設(shè)直線
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,
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是直線
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上任意一點,它的“對偶點”為
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,則存在
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使得
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,即
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,又
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,消去
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,得
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.
故
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在過點
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的圓
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上.
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
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
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