cos13°cos133°+sin13°sin47°=______.-数学

题目简介

cos13°cos133°+sin13°sin47°=______.-数学

题目详情

cos13°cos133°+sin13°sin47°=______.
题型:填空题难度:偏易来源:不详

答案

cos13°cos133°+sin13°sin47°
=-cos13°cos47°+sin13°sin43°
=-cos(47°+13°)
=-cos60°
=-class="stub"1
2

故答案为:-class="stub"1
2

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