不用计算机求sinπ/8,cosπ/8
不用计算机求sinπ/8,cosπ/8
求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8
求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8!急救急救
不用计算器求值sinπ\8 cosπ\8=sin^2 π\12-cos^2 π\12=化简:(cosx+sinx)^2=
计算机计算sin cos
已知向量m=(Cosθ,Sinθ)和n(根号2 -Sinθ,Cosθ),且Im+nl= 求Cos(θ/2+π/8)
不用计算器,求(cos(π/8))^4+(cos(3π/8))^4+(cos(5π/8))^4+(cos(7π/8))^
初中的锐角三角函数,非30,45,60等特殊角的三角函数怎么求啊?不用计算机,自己笔算,比如Sin∠55°,或者COS∠
(cosπ/8+sinπ/8)(cos^3π/8-sin^3π/8)
(cos π/8+ sin π/8 ) (cos^3 π/8+sin^3 π/8 )的值.
8sin(π/32)cos(π/32)cos(π/16)cos(π/8),求值
求下列各式的值.第一题sin 15°cos 15° 第二题cos²π/8-sin²π/8