COS(π/7)+COS(3π/7)+COS(5π/7)化简求值,

化简cos^8(π/8)+cos^8(3π/8)+cos^8(5π/8)+cos^8(7π/8) cos^2 π/8+cos ^2 3π/8+ cos^2 5π/8+cos^2 7π/8=? COS(π/7)+COS(3π/7)+COS(5π/7)化简求值, Cos[π/7] + Cos[2 π/7] + Cos[3 π/7] + Cos[4 π/7] + Cos[5 π/7] + Cos[6 π/7] + Cos[7π/7]过程思路 不要只有答案哦 cos(π/7)cos(2π/7)cos(3π/7)的值!π为圆周率,在这里表示弧度! cos(π/7)cos(2π/7)cos(3π/7)的值!π为圆周率,在这里表示弧度! cos(π/7) + cos(6π/7) =几 -cos(7/4) =cos(π-(7/4)) 函数 (4 20:28:50)cos^4 (π /8)+cos^4(3π/8)+cos^4(5π/8)+cos^4(7π/8) = 不用计算器,求(cos(π/8))^4+(cos(3π/8))^4+(cos(5π/8))^4+(cos(7π/8))^4的值 化简求值cos(π/7)cos(2π/7)cos(4π/7) cos 2π/7 +cos 4π/7 +cos 6π/7=? 求cos(2π/7)*cos(4π/7)*cos(6π/7)的值 请问cos(2π/7)+cos(4π/7)+cos(6π/7)=?, 求证cos2π/7+cosπ/3=cosπ/7+cos3π/7 cos^3(-π-α) 计算：cos（π/5)+cos（2π/5)+cos(3π/5)+cos(4π/5) cos^2α+cos^2(α+π/3)-cosαcos(α+π/3)化简