问题
选择题
化简
|
答案
=sin235°- 1 2 cos10°•cos80°
=-2sin235°-1 2cos10°•sin10°
=-1cos70° cos70°
故选C．
搜题请搜索小程序“爱下问搜题”
化简
|
=sin235°- 1 2 cos10°•cos80°
=-2sin235°-1 2cos10°•sin10°
=-1cos70° cos70°
故选C．