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[几何] 求教一道立体几何题

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Gadfly Posted 2015-1-26 23:23 |Read mode
棱长为1的正方体AC1,点M在与正方体的各棱都相切的球面上运动,点N在三角形ACB1的外接圆上运动,则线段MN长度的最小值是

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爪机专用 Posted 2015-1-26 23:39
目测$(\sqrt3-\sqrt2)/2$

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爪机专用 Posted 2015-1-27 01:38
也就是半条体对角线减去棱切球半径

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 Author| Gadfly Posted 2015-1-27 09:05
为什么是半个体对角线呢

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 Author| Gadfly Posted 2015-1-27 09:16
已经搞懂,大神,谢谢啦

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