sec80度减tan60度乘csc80度等于大神们帮帮忙
<p>问题：sec80度减tan60度乘csc80度等于大神们帮帮忙<p>答案：↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">林金的回答：<div class="content-b">网友采纳 sec80°-tan60°*csc80°=1/cos80°-√3*1/sin80°=(sin80°-√3cos80°)/(cos80°sin80°)=2sin(80°-60°)/(1/2sin160°)=4sin20°/sin160°=4注：sinx=sin(180°-x),正割,余割的定义必须清楚.
页:
[1]