三角函数:(sin^2)(60度)+(cos^2)(270度)-(tan^2)(60度)
<p>问题：三角函数:(sin^2)(60度)+(cos^2)(270度)-(tan^2)(60度)<p>答案：↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">黄晓鸣的回答：<div class="content-b">网友采纳 ∵(sin^2)(60°)=(根号3/2)^2=3/4(cos^2)(270°)=(cos^2)(270°-180°)=(cos^2)(90°)=0(tan^2)(60°)=(根号3)^2=3∴(sin^2)(60°)+(cos^2)(270°)-(tan^2)(60°)=3/4+0-3=-9/4
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