化简cos2x/sin（x+π/4）急!

已知函数f(x)=（4cos^4x-2cos2x-1）/[sin(π/4+x)·sin^2(π/4-x)]化简 已知函数f(x)=（4cos^4x-2cos2x-1）/[sin(π/4+x)·sin(π/4-x)]化简 已知函数f(x)=cos2x/[sin(π/4-x)] 化简函数f（x）=[(1+cos2x)²-2cos2x-1]/[sin(π/4+x）*sin(π/4-x)] f（x）=4sin^2（π/4+x）-2根号3cos2x-1化简! f(x)=((1+cos2x)^2-2cos2x-1)/(sin(π/4+x)sin(π/4-x)) 已知函数f（x）=2sin²（π/4+x）-根号3cos2x 已知函数f(x)=2sin^2（π/4+x）-根号3cos2x y=2cos2x+sin平方x-4cosx.化简 化简：2cos2x+2sin^2 x+cos(-x)分之sin2x+sin(π-x)=___________ 已知函数f（x）=sin（π-x）sin（π2-x）+cos2x 若(cos2x)/[sin(x-π/4)]=（-根号2）/2,则cosx+sinx=?