求y=sin(1/2x+π/3)-cos(1/2x-π/6)+7的周期

Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y) y =(cos^2) x - sin (3^x),求y' 已知Sin x+Sin y=1/2,Cos x+Cos y=根号3/3,求S求Sin(x-y)/2 sin^2x+cos^2y=1/2 求3sin^2x+sin^2y的最值 已知sinx=3/5,x∈(π/2,π),求【sin(x+y)+sin(x-y)】/【cos（x+y）+cos（x-y）】的值 求函数y=cos(9/2π+x)+sin^2x的最大值和最小值还有一题 已知sinx+cosx=1/2,求sin^3x+cos^3x和sin^4x+cos^2x 当cos^2x-cos^2y=√3/2时,求sin(x+y）×sin(x-y) sin(x+y)sin(x-y)=k,求cos^2x-cos^2y sin(x+y)cosx+cos(x+y)sinx=1/3 x∈(3π/2,2π) 求cos(2x+π/4) 求y=（1+cos x)/(sin x+cos x+2)的值域. y=1-sin(2x)/sin(x)-cos(x)求T.最值 2sin^2x+cos^2y=1,求sin^2x+cos^2y的取值范围 求y=sin＾2(x)+3sin(x)cos(x)-2cos＾2(x)的最大值 求y=sin x +2sin x cos x -3cos²x 的周期和值域, 求y=sin(2x+π/3)+cos(2x-π/6)的单调区间 y=sin(π/3-2x)+cos(2x)的周期怎么求? y=1/2cos^2x+sinxcosx+3/2sin^2x 求单调区间 问道三角函数题已知sin(x)-sin(y)=-(2/3);cos(x)-cos(y)=(2/3);求cos(x-y)