y=4sin(x-π/4)cos(x+π/4)怎么化简啊!

函数y=sin(x)cos(x+ π/4)+cos(x)sin(x+π/4)的最小正周期是 y=2cos(x/4+ π/3)-3sin(x- π/4)y=sin(4x- π/3)-cos(3x+π/2) 求函数y=sin^4x+cos^4x,x(0,π/6)的最小值 求函数y=cos(9/2π+x)+sin^2x的最大值和最小值还有一题 已知sinx+cosx=1/2,求sin^3x+cos^3x和sin^4x+cos^2x y=4sin(3x+(π/4))+3cos(3x+(π/4)),求周期 y=4sin(x-π/4)cos(x+π/4)怎么化简啊! 函数y=cos^4πx-sin^4πx的最小正周期是什么 y=2sin(x-π/4)cos(x+π/4)+1化简 y=sin(2x-π/4)+cos(3x+π/3)的导数 y=sinπx+cosπx的周期 y=√2sin(2x+π／4)-1/2cos²x 化简~急用~ 化简y=sin^4x-cos^4x, y=sin^4x+cos^4x的值域 sin(x+y)cosx+cos(x+y)sinx=1/3 x∈(3π/2,2π) 求cos(2x+π/4) 确定下列函数的定义域1）y=√[lg(cos x)]2) y={tan[x-π/4)]*√(sin x)}/lg(2cos x-1) 求证:(sin 2x /(1-cos 2x) )·(sin x /(1+sin x))=tan (π/4-x/2). 求微分方程COS xSin ydy=COS y Sin xdx,Y|x=0 =π/4的特解 函数y=cos^4x-sin^4x的最小正周期y=(cos^2x+sin^2x)(cos^2x-sin^2x)为什么等于cos^2x-sin^2x=cos2x谢谢