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sin15°×sin30°×sin75°

分类: 作业答案 • 2021-12-31 14:18:35

问题描述：

sin15°×sin30°×sin75°

答

sin30=1/2 原公式=1/2*sin（15）*sin（π/2－15）=1/2*sin(15)*cos(15) =1/4*(2*sin(15)cos(15))=1/4*sin(30)=1/8

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sin15ºsin30ºsin75º的值