求值:(sin7°+cos15°sin8°)/(cos7°+sin15°sin8°)
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![求值:(sin7°+cos15°sin8°)/(cos7°+sin15°sin8°)](/uploads/image/z/4336389-45-9.jpg?t=%E6%B1%82%E5%80%BC%EF%BC%9A%EF%BC%88sin7%C2%B0%2Bcos15%C2%B0sin8%C2%B0%EF%BC%89%2F%EF%BC%88cos7%C2%B0%2Bsin15%C2%B0sin8%C2%B0%EF%BC%89)
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 =sin15
cos8/cos15cos8=tan
15=tan(45-30)=2-
根号3