帮帮化简sin^4x-cos^4x(sin^2x+cos^2x )(sin^2x-cos^2x)怎么得sin^2x-cos^2x?麻烦

帮帮化简sin^4x-cos^4x(sin^2x+cos^2x )(sin^2x-cos^2x)怎么得sin^2x-cos^2x?麻烦 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? 化简sin^4x-sin^2x+cos^2x 化简:sin^4 x-sin^2 x+cos^2 x 化简cos^4x+sin^4x 化简:cos^4(X)-sin^4(X) 化简sin^4x+cos^2x 化简(sin^2x-cos^4x+cos^2x-sin^4x)/(sin^2x-cos^6x+cos^2x-sin^6x) (6cos^4x-sin^2x-1)/(2(2cos^2x -1))怎么化简 化简求值:sin(π/4-3x)*cos(π/3-3x)-cos(π/6+3x)*sin(π/4+3x) 化简下面的三角函数f(x)=sin^2x+2√3sin(x+∏/4)cos(x-∏/4)-cos^2-√3 函数fx=cos(2x-π/3)+2sin(x-π/4)sin(x+π/4)怎么化简? 求sin(π/2+2x)=2sin(π/4+x)cos(π/4+x)的化简过程 化简 1-sin^4x-cos^4x/1-sin^6x-cos^6x 化简(1-cos^4x-sin^4x)/(1-cos^6x-sin^6x) 求值：(1-sin^6 x-cos^6 x)/(1-sin^4 x-cos^4 x) 证明sin^4x-cos^4x=sin^2x-cos^2x 求证sin^4x-cos^4x=sin^2x-cos^2x