在直角坐標(biāo)系
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中,已知點
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,點
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在
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三邊圍成的區(qū)域(含邊界)上
(1)若
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,求

;
(2)設(shè)
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,用
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表示
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,并求
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的最大值.
(1)
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;(2)

,1.
試題分析:(1)因為
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,所以
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,即得
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,最后求得
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;
(2)因為
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,所以
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,即
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,兩式相減得:
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令
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,點
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在
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三邊圍成的區(qū)域(含邊界)上,當(dāng)直線
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過點
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時,
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取得最大值1,故
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的最大值為1.
試題解析:(1)因為
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所以
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即得

所以
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(2)
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
即
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兩式相減得:
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令
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,由圖可知,當(dāng)直線

過點
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時,
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取得最大值1,故

的最大值為1.
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