问题描述: 若cos(π+α)=-1/2,3π/2 1个回答 分类:数学 2014-11-06 问题解答: 我来补答 cos(π+α)= sin(-π/2 -α)= -sin(π/2 +α)= -cos(-α)= -cosα= -1/2则cosα=1/2,sin(2π-α)=sin(-α)= -sinα3π/2 展开全文阅读