作业帮cosπ/9cos2π/9cos23π/9
来源：学生作业帮助网 编辑：作业帮 时间：2024/07/08 20:12:46
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cosπ/9cos2π/9cos23π/9
cosπ/9cos2π/9cos23π/9
cosπ/9cos2π/9cos23π/9
cosπ/9cos2π/9cos23π/9
=[2sinπ/9cosπ/9cos2π/9cos23π/9]/2sinπ/9
=[sin2π/9cos2π/9cos(2π+5π/9)]/2sinπ/9
=[sin4π/9cos5π/9]/4sinπ/9
=-[sin4π/9cos4π/9]/4sinπ/9
=-(sin8π/9)/8sinπ/9
=-(sinπ/9)/8sinπ/9
=-1/8
cosπ/9cos2π/9cos23π/9
cosπ/9*cos2π/9*cos4π/9=?
求COSπ/5*COS2π/5
cosπ/5×cos2π/5=
COSπ/5乘以COS2π/5
cosπ/5×cos2π/5
cosπ/5cos2π/5
cosπ/5cos2π/5=?
化简cosπ/9*cos2π/9*cos3π/9*cos4π/9
求cosπ/9*cos2π/9*cos3π/9*cos4π/9
cosπ/9cos2π/9cos3π/9cos4π/9=
求cosπ/9*cos2π/9*cos4π/9的值如题
cosπ/9*cos2π/9*cos4π/9怎么算的?
急 、COSπ/9*COS2π/9*COS4π/9=?同样,
cosπ/5 - cos2π/5 怎样变成 cosπ/5 + cos2π/5rt
化简cos2α+cos2(π/3+α)+cos2(π/3-α)化简cos²α+cos²（π/3+α）+cos²（π/3-α）
sinπ.cosπ.sin2π.cos2π分别是多少
求值:cosπ/7*cos2π/7*cos3π/7