sin^2(x+y)-cos(x+y)sin(x+y)-3cos^2(x+y)的值
y =(cos^2) x - sin (3^x),求y'
设sin(x+y)sin(x-y)=m,则cos^2x-cos^2y的值
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y)
化简sin(2x-y)*sin y+cos(2x-y)*sin y
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)的最值 用向量解
sin^2x+cos^2y=1/2 求3sin^2x+sin^2y的最值
化简sin(x+y)cos(x-y)+cos(x+y)sin(x-y)
已知cos^2x-cos^2y=根号3/2,则sin(x+y)·sin(x-y)的值
2sin^2x+cos^2y=1,求sin^2x+cos^2y的取值范围