高一数学,谢谢
求证16cos24cos48cos96cos168=1
参考答案:题干应该是cos192 吧!
左边=16cos24cos48cos96cos192*sin24/sin24
=8sin48*cos48*cos96*cos192/sin24
=4sin96*cos96*cos192/sin24
=2sin192*cos192/sin24
=sin384/sin24
=sin24/sin24
=1
求证16cos24cos48cos96cos168=1
参考答案:题干应该是cos192 吧!
左边=16cos24cos48cos96cos192*sin24/sin24
=8sin48*cos48*cos96*cos192/sin24
=4sin96*cos96*cos192/sin24
=2sin192*cos192/sin24
=sin384/sin24
=sin24/sin24
=1