cosπ/5·cos2π/5等于多少?
cosπ/5·cos2π/5等于多少?
cosπ/5 乘以cos2π/5等于多少
(cosπ/5)(cos2π/5)的值等于
COSπ/5乘以COS2π/5
求COSπ/5*COS2π/5
cos^2(2/π-a)+cos2^2(6/π+a)等于多少
cosπ/5cos2π/5的值等于 :麻烦过程竖着写 横着写看不懂~最好一步一步写清楚~
cosπ/5*cos2π/5 =(2sinπ/5*cosπ/5*cos2π/5)/(2sinπ/5) =(sin2π/5
(二倍角的三角函数)cosπ/5cos2/5π的值是______cosπ/5cos2π/5 =sinπ/5cosπ/5c
已知cosθ等于负5分之3,且θ属于(π,2分之3π),求cos2分之θ的值值
已知cosθ等于负5分之3,且θ属于(π,2分之3π),求cos2分之θ的值
cos派/5cos2派/5