cos(π/4+x)=4/5x∈（17π/12,7π/4）,求（sin2x+2sin²x）/（1-tanx）

cos(2x-π)/[根号2cos(x+π/4)]=-1/5,0 cos(π/4+x)=3/5,17π/12 cos(π/4+X)=3/5,17π/12 cos(π/4+x)=3/5,17π/12 cos(π/4+x)=3/5,17π/12 cos(π/4+x)=3/5,17/12π cos(π/4+x)=3/5,17π/12 cos(π/4+x)=3/5,17π/12 cos(π/4+x)=3/5,-17π/12 化简：cos(π/4-x)乘cos(π/4+x) 化简sin(3π-x)cos(x-3/2)cos(4π-x)/tan(x-5π)cos(π/2+x)sin(x-5/2π) 化简sin(3π-x)cos(x-3/2)cos(4π-x)/tan(x-5π)cos(π/2+x)sin(x-5/2π) 三角函数解方程 (cos 3x)^3+ (cos 5x)^3 = 8 (cos 4x)^3 (cos x)^3 y=cos(π/4-x)求导 已知sin[a-b]cos a-cos[b-a]sin a=3/5,b是第三象限角,求sin[b+5π/4]的值第一题1/2cos x-√3/2sin x第二题√3sin x+cos x第三题√2[sin x-cos x]第四题√2cos x-√6sin x 已知f(x)=sin(π/6-x)^2-cos(π/4+x)^2+cos(π/6)cos(π/6-2x)化简f(x) 函数y=sin(x)cos(x+ π/4)+cos(x)sin(x+π/4)的最小正周期是 已知cos（x+45º)=3／5且17π/12＜x＜7π/4,求(sin2x+2cos²x)／1-tanx的值注意!括号里加的是cos^2x