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

分类: 作业答案 • 2022-03-19 17:16:32

问题描述：

答

(sin24°cos6°-sin66°sin6°)/(sin21°cos39°-cos21°sin39°)
=(sin24°cos6°-cos24°sin6°)/(sin21°cos39°-cos21°sin39°)
=sin18°/sin(-18°)=-1