已知sin(a/2)=3/5,a为锐角,求sin2a的值答案是336/625,
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![已知sin(a/2)=3/5,a为锐角,求sin2a的值答案是336/625,](/uploads/image/z/2478781-37-1.jpg?t=%E5%B7%B2%E7%9F%A5sin%28a%2F2%29%3D3%2F5%2Ca%E4%B8%BA%E9%94%90%E8%A7%92%2C%E6%B1%82sin2a%E7%9A%84%E5%80%BC%E7%AD%94%E6%A1%88%E6%98%AF336%2F625%2C)
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已知sin(a/2)=3/5,a为锐角,求sin2a的值答案是336/625,
已知sin(a/2)=3/5,a为锐角,求sin2a的值
答案是336/625,
已知sin(a/2)=3/5,a为锐角,求sin2a的值答案是336/625,
sin(a/2)=3/5,a为锐角 推出cos(a/2)=4/5
sin2a=2sina*cosa=4sin(a/2)*cos(a/2)*[1-2sin(a/2)*sin(a/2)]
=336/625