1−2sin(π+2)cos(π+2)=_．
问题描述：
=______．
1−2sin(π+2)cos(π+2)
答
=
1−2sin(π+2)cos(π+2)
=
1−2sin2cos2
(sin2−cos2) 2
∵sin2＞cos2
∴原式=sin2-cos2
故答案为：sin2-cos2