y=sin^4 x/4 + cos^4 x/4 求导数 …………

化简y=sin^4x-cos^4x, y=sin^4x+cos^4x的值域 已知sinθ+cosθ=2sinx,sinθcosθ=sin²y,求证：4cos²2x=cos²2y y=sin²x*cos^4 的最大值 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 y=4√2sin x cos x+cos 2x 的值域是 函数y=sin(x)cos(x+ π/4)+cos(x)sin(x+π/4)的最小正周期是 求函数y=7-4sin(x)cos(x)+4cos^2(x)-4cos^4(x)值 6-4x-x^2=5/|sin(y/x)cos(y/x)|的解 y=sin^4x+cos^4x=(sin^2x+cos^2x)^2-2sin^2xcos^2x 这一步是怎么来的? 求y=sin^5x ,y=cos(4x+3) 的导数, 已知cos(x+y)cosy+sin(x+y)siny=4/5,求tanx的值 y=sin^4x/4+cos^4x的导数怎么求?打错了，是y=sin^4(x/4)+cos^4(x/4) y=2cos(x/4+ π/3)-3sin(x- π/4)y=sin(4x- π/3)-cos(3x+π/2) y=sin^2x-3sinxcosx+4cos^2x是否等于y=sin^2x+cos^2x+3cos^2x-3/2*sin2x?y=sin^2x-3sinxcosx+4cos^2xy=sin^2x+cos^2x+3cos^2x-3/2*sin2x=1+3cos^2x-3/2*sin2x=1+3（1-sin^2x）-3/2*sin2x=-3sin^2x-3/2*sin2x+4 y=sin^4-cos^4周期y=sin^4-cos^4的周期 证明sin^4x-cos^4x=sin^2x-cos^2x 求证sin^4x-cos^4x=sin^2x-cos^2x