作业帮已知cos(15°+a)=4/5,a为锐角,求[sin(435°-a)+sina(a-165°)]/cos(195°+a)的值
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![已知cos(15°+a)=4/5,a为锐角,求[sin(435°-a)+sina(a-165°)]/cos(195°+a)的值](/uploads/image/z/965956-4-6.jpg?t=%E5%B7%B2%E7%9F%A5cos%2815%C2%B0%2Ba%29%3D4%2F5%2Ca%E4%B8%BA%E9%94%90%E8%A7%92%2C%E6%B1%82%5Bsin%28435%C2%B0-a%29%2Bsina%28a-165%C2%B0%29%5D%2Fcos%28195%C2%B0%2Ba%29%E7%9A%84%E5%80%BC)
已知cos(15°+a)=4/5,a为锐角,求[sin(435°-a)+sina(a-165°)]/cos(195°+a)的值
已知cos(15°+a)=4/5,a为锐角,求[sin(435°-a)+sina(a-165°)]/cos(195°+a)的值
已知cos(15°+a)=4/5,a为锐角,求[sin(435°-a)+sina(a-165°)]/cos(195°+a)的值
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