问题描述: (sin2a+cos2a-1)(sin2a-cos2a+1)除以sin4a=根号3,a为锐角,求角a的值, 1个回答 分类:数学 2014-11-11 问题解答: 我来补答 (sin2a+cos2a-1)(sin2a-cos2a+1)=sin²2a-(cos2a-1)²=-2cos²2a+2cos2a=根号3 sin4a,即-2cos²2a+2cos2a=2√3sin2acos2a ,即2cos2a(1-cos2a-√3sin2a)=0,即4cos2asina(sina-√3cosa)=0即a=45°或a=60° 展开全文阅读