化简sin^2x+sin^2y-sin^2xsin^2y+cos^2xcos^2y
求证 cos*xcos*y + sin*xsin*y + sin*xcos*y + xin*ycos*x = 1
化简sin(2x-y)*sin y+cos(2x-y)*sin y
求函数y=2sin xcos x+2sin x+2cos x+4的值域
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
y =(cos^2) x - sin (3^x),求y'
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
y=sin^2x+sinxcoswx+cos^2x 化简
化简y=(cos x)^2+sin x -2 谢谢
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)
tan(x+y)tan(x-y)=sin^2x-sin^2y/cos^2x-sin^2y 顺便问一下. tan,sin,
求函数y=sin^4x+cos^4x+4sin^2xcos^2x-1的最小正周期和值域