问题
解答题
求值：
|
答案
原式=1-2sin10°cos10° cos10°- 1-cos2170°
=sin210°-2sin10°cos10°+cos210° cos10°- sin2170°
=|sin10°-cos10°| cos10°-|sin170°|
=cos10°-sin10° cos10°-|sin(180°-10°)|
=
=1cos10°-sin10° cos10°-sin10°
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