tan30°= .
考点分析:
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将矩形ABCD沿AE折叠,使点D落在D′处,已知∠CED′=60°,DE=1,则DD′的长为( )
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D.3
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正比例函数y=x与反比例函数y=
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二次函数y=ax
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如图,CD是⊙O的直径,AB是弦(不是直径),AB⊥CD于点E,则下列结论正确的是( )
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=
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∠AEC
D.△ADE∽△CBE
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