y=7-4sin xcos x+4cos^2 x-4cos^4 x的最大值和最小值?

y=7-4sin xcos x+4cos^2 x-4cos^4 x的最大值和最小值? 求函数y=2sin xcos x+2sin x+2cos x+4的值域 y=sin^4x+cos^4x=(sin^2x+cos^2x)^2-2sin^2xcos^2x 这一步是怎么来的? 求证 cos*xcos*y + sin*xsin*y + sin*xcos*y + xin*ycos*x = 1cos*xcos*y + sin*xsin*y + sin*xcos*y + sin*ycos*x = 1注意：[*] 的意思是 [ ^2 ]写下左右过程.. 求证sin^4x+cos^4x=1-2sin^2xcos^2x sin^4x+cos^4x=1-2sin^2Xcos^2X谢谢额 化简sin^4x+sin^2xcos^2x+cos^2x=?(请写过程) 求证 sinˇ4X+sin²Xcos²X+cos²X = 1 sin^4+sin^2xcos^2x+cos^2x 证明 =1 sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos^2x+cos^4x 是根据什么化简的? sin^8X+cos^8X+4sin^2Xcos^2x-2sin^4xcos^4X(化简） 求函数y=sin^4x+cos^4x+4sin^2xcos^2x-1的最小正周期 值域 求值域 y=sin x-cos x+sin xcos x sin^4x-sin^2xcos^2x+cos^4x =(sin^2x+cos^2x)^2-3sin^2xcos^2x 那么这个依据呢?老师 求sin^4x+cos^4x=1-2sin^2xcos^2x的详细答案! 已知tanx=-3/4,求2sin^2 x+3sin xcos x-cos^2 x 化简：cos^4x+sin^2xcos^2x+cos^2x 化简cos^4x+sin^2xcos^2x+sin^2x