8sinπ/8-cos^2π/8如何做 急

8sinπ/8-cos^2π/8如何做 急 求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8 sinπ/8×cosπ/8 sinπ/8×cosπ/8 sinπ/8*cosπ/8 sinπ/8cosπ/8=( ) 化简sin(α-5π)/cos(3π-α)×cos(π/2-α)/sin(α-3π)×cos(8π-α)/sin(-α-4π) 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cos^4(π/8)+sin^4(π/8)=____ 怎么做的? (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. cos 5π/8 cos π/8 + sin 5π/8 sin π/8= 化简：[1+2sin(α+2π)*cos(α-2π)]/[sin(α+4π)+cos(α+8π)] 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 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 2sinπ/8cosπ/8怎么得到sinπ/4?