sin21°cos24°+cos21°sin24°
1个回答
原式
=sin(21+24)°
=sin45°
=√2/2
相关问题
求值sin21°cos24°+cos21°sin24°过程
(sin39° -sin21°)/(cos39°-cos21°)
=cos24cos36-sin24sin36① =cos(24+36)②
求sin39°-sin21°/cos39°-cos21°的值
cos24°cos54°-sin24°cos144°=?
化简:(1)cos24°cos69°-sin24°sin111°
cos24°cos54°-sin24°cos144°急!
求值:sin21°cos81°-sin69°cos9°
求值:sin21°cos81°-sin69°cos9°=______.
cos24度cos69度+sin24度sin69度=?