Question

化简 1-2sin10°cos10° sin170°- 1-si n 2 170° =______

化简 1-2sin10°cos10° sin170°- 1-si n 2 170° =______．

Answer 1

1-2sin10°cos10° sin170°- 1-si n 2 170° = (sin10°-cos10° ) 2 sin10°- co s 2 10° = cos10°-sin10° sin10°-cos10° =-1． 故答案为：-1．