COSx求和
发布网友
发布时间：2022-11-03 02:27
共1个回答
热心网友
时间：2023-10-27 01:34
解：∵cos(π/6)+cos(5π/3)=cos(11π/6)
cos(π/3)+cos(3π/2)=cos(11π/6)
∴原式子=5cos(11π/6)
=5cos(2π-π/6)
=5cos(π/6)
=(5根号3)/2
