摘要：25．如图1.正方形和正三角形的边长都为1.点分别在线段上滑动.设点到的距离为.到的距离为.记为(当点分别与重合时.记)． (1)当时.求的值, (2)当为何值时.点落在对角形上?请说出你的理由.并求出此时的值, (3)请你补充完成下表: 0.03 0 0.29 0.29 0.13 0.03 (4)若将“点分别在线段上滑动 改为“点分别在正方形边上滑动 ．当滑动一周时.请使用(3)的结果.在图4中描出部分点后.勾画出点运动所形成的大致图形． (参考数据:．) 25．解:(1)过作于交于.于． .. .．······················································································ 2分 .．························································································· 3分 (2)当时.点在对角线上.其理由是:·········································· 4分 过作交于. 过作交于． 平分..． ..． .． .． 即时.点落在对角线上．································································ 6分 (以下给出两种求的解法) 方法一:.． 在中.. ．·········································································· 7分 ．························································································ 8分 方法二:当点在对角线上时.有 .··························································································· 7分 解得 ．························································································ 8分 (3) 0.13 0.03 0 0.03 0.13 0.29 0.50 0.50 0.29 0.13 0.03 0 0.03 0.13 ································································ 10分 (4)由点所得到的大致图形如图所示: ··························································································· 12分 说明:1．第(2)问回答正确的得1分.证明正确的得2分.求出的值各得1分,

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