sin(Π/2 - x)=cos(Π/4 - x/2)、以及 1-cos(Π/2 - x)=sin(Π/4 - x/2)

sin(x+1/2π)=cosx?还是cos-x 函数f(x)=-√2(sin2x+π/4)+6 sin x cos x-2cos²x+1 已知函数f(x)=(1+1/tanx)sin(x)^2 -2sin(x+π/4)*cos(x+π/4) 已知f(x)=cos^2x+sinxcosx g(x)=2sin(x+π/4)sin(x-π/4) 求证（cos^2 x-sin^2 x)(cos^4 x+sin^4 x)+1/4 sin 2x sin 4x=cos 2 已知函数f(x)=cos(2x-π/3)+sin^2 x-cos^2 x 化简2sin^2[(π/4)+x]+根号3（sin^x-cos^x）-1 已知函数f(x)=cos(2x-π\3)+sin²x-cos²x 化简f(x)=(1+√2*cos(2x-π/4))/sin(π/2-x) 已知f(x)=cos^2x/1+sin^2x求f'(π/4) 已知函数f(x)=sin²(π/4+x)+cos²x+1/2求最值 证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4