求值(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/20 11:11:42
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求值(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)
求值(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)
求值(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)
=(sin(15-8)+cos15sin8)/(cos(15-8)-sin15sin8
=(sin15cos8-cos15sin8+cos15sin8)/(cos15sin8+sin15cos8-sin15sin8)=sin15/cos15
=tan15
=tan(45-30)
=2-根3
=(sin(15-8)+cos15sin8)/(cos(15-8)-sin15sin8
=(sin15cos8-cos15sin8+cos15sin8)/(cos15sin8+sin15cos8-sin15sin8)=sin15/cos15
=tan15
=tan(45-30)
=2-根3
额。上面忘登陆了。