sinπ/8cosπ/8=( )

sinπ/8cosπ/8=( ) cos 5π/8 cos π/8 + sin 5π/8 sin π/8= 求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8 sinπ/8×cosπ/8 sinπ/8×cosπ/8 sinπ/8*cosπ/8 cos^6(π/8)-sin^6(π/8)=求值,[cos^2(π/8)-sin^2(π/8)][cos^4(π/8)+sin^4(π/8)+cos^2(π/8)sin^2(π/8)]=cos(π/4)[1-cos^2(π/8)sin^2(π/8)]=cos(π/4)[1-[sin^2(π/4)]/4]==7√2/16 计算sin²π/8-cos²π/8= sin^4π/8-cos^4π/8=? cos(3π/8)*sin(5π/8)=? sinθcosθ=1/8,θ∈(π/4,π/2),求cosθ-sinθ的值 cos(π/3-α)=1/8,则cosα+（根号3）sinα的值为____已知cosα-cosβ=1/2,sinα-sinβ=1/3,求cos(α+β)的值 为什么-[cos²(π/8)-sin²(π/8)]=-cos(π/4) (cosπ/8+sinπ/8)（cos^3π/8-sin^3π/8） (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. 若 sinθ ·cosθ=1/8,求 sinθ +cosθ?怎样用单位圆确定 sinθ 和cosθ大若 sinθ ·cosθ=1/8,求 sinθ +cosθ?怎样用单位圆确定 sinθ 和cosθ谁大谁小?θ属于（π/4，π/2），关键是怎样用单位圆比较大小 8sin(π/32)cos(π/32)cos(π/16)cos(π/8),求值