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已知\(\Delta ABC\)中,\(\angle C=90^{\circ}\),\(\overline{AC}=12\),\(\overline{BC}=5\),\(D\)為斜邊\(\overline{AB}\)上動點,今沿著\(\overline{CD}\)將\(\Delta BCD\)折起,使得\(BCD\)面垂直\(ACD\)面,
(1)求\(\overline{AB}\)的最小值?
(2)在\(\overline{AB}\)有最小值時,設\(BAC\)面與\(DAC\)面的兩面角為\(\theta\),則\(tan\theta=\)?
[解答]
圖"立起來"想像一下就可以參考了
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2021-8-9 01:13