已知cos^2x-cos^2y=根号3/2,则sin(x+y)·sin(x-y)的值
已知cos^2x-cos^2y=根号3/2,则sin(x+y)·sin(x-y)的值
设sin(x+y)sin(x-y)=m,则cos^2x-cos^2y的值
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y
已知函数y=sin(x/2)+根号3*cos(x/2),x属于R
已知函数y=4 cos²x+4倍根号3 sin x cos x-2,x∈R.
y =(cos^2) x - sin (3^x),求y'
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
函数y=根号3 cos²x+sin x cos x-根号3/2的周期是?
已知函数y=(sin x+ cos x)(sin x+cos x)+2cos x*cos x ,求它的递减区间