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(sin24°cos6°-sin66°sin6°)/(sin21°cos39°-cos21°sin39°)化简后得

题目详情
(sin24°cos6°-sin66°sin6°)/(sin21°cos39°-cos21°sin39°)化简后得
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答案和解析
(sin24°cos6°-sin66°sin6°)/(sin21°cos39°-cos21°sin39°)
=(sin24°cos6°-cos24°sin6°)/(sin21°cos39°-cos21°sin39°)
=sin18°/sin(-18°)=-1