求值:(sin15°cos15°-sin20°)÷(cos15°cos5°-cos20°)
求cos15°-tan15°/cos15°+sin15°
求值:cos20°sin20°
求值(sin9°cos15°-sin24°)/(sin9°sin15°+cos24°)
求值:(sin9°+sin6°cos15°)/(cos9°-sin6°sin15°)
(cos15°-cos75°)(sin75°+sin15°)=?
tan15°+cos15°/sin15°的值 求详解
求sin15°+tan30°cos15°的值
(cos15°-cos75°)(sin75°+sin15°)怎么化简?
cos75°cos15°+sin75°sin15°的值为( )
求(sin8°+sin7°cos15°)/(cos8°-sin7°sin15°)的值
tan15°+cos15°等于
求值 1.cos80度.cos20度+cos10度.sin20度=--------- 2.根号3sin15度+cos15