化简：cos(60°-a)-cos(60°+a)=_数学解答

化简：cos(60°-a)-cos(60°+a)=

人气：429 ℃　时间：2020-04-21 23:02:39

解答

化简：cos(60°-a)-cos(60°+a)
=cos60°cosa+sin60°sina-(cos60°cosa-sin60°sina)
=cos60°cosa+sin60°sina-cos60°cosa+sin60°sina
=2sin60°sina
=2×√3/2sina
=√3sina