题目内容
sin(-1 071°)sin99°+sin(-171°)sin(-261°)=___________________.
解析:原式=sin(-3×360°+9°)cos9°+sin171°·sin261°=sin9°·cos9°+sin9°·(-cos9°)=0.
答案:0
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轻巧夺冠周测月考直通中考系列答案题目内容
sin(-1 071°)sin99°+sin(-171°)sin(-261°)=___________________.
解析:原式=sin(-3×360°+9°)cos9°+sin171°·sin261°=sin9°·cos9°+sin9°·(-cos9°)=0.
答案:0
轻巧夺冠周测月考直通中考系列答案