cos2x/sin{x-π/4}=-根号2/2求cosx+sinx的值

若(cos2x)/[sin(x-π/4)]=（-根号2）/2,则cosx+sinx=? 若cos2x/sin(x-π/4）=-根号2/2,sin2x=? cos2x/sin{x-π/4}=-根号2/2求cosx+sinx的值 sin2x-cos2x=根号2·sin(2x-π/4)?怎么变的 sin2x-cos2x=根号2sin(2x-π/4) 为什么啊 在区间[-π/2,π/2]上,sin2x+cos2x=根号2的x值为sin2x+cos2x怎么变成根号2*sin(2x+派/4) 2sin(x-π/4)sin(x+π/4)=?答案是-cos2x 还是cos2x 已知sin(x-π/6)=根号3/3 求3sin2x+根号3cos2x 若sin(x+4/π）/cos2x=-根号2,则cos(x+4/π)的值为? f（x）=4sin^2（π/4+x）-2根号3cos2x-1化简! 怎样把f(x)=sin2x-cos2x+1化成根号2sin（2x-π/4)+1 已知函数f(x)=cos2x/[sin(π/4-x)] sin2x+cos2x+2如何化简sin2x+cos2x如何化为根号2sin(2x+π/4)? 求函数y=根号3sin(π/3-2x)-cos2x的最小值（根号3）sin sin2x+cos2x+2=根号2倍的sin(2x+π/4)+2怎么出来的, 为什么sin2x+cos2x=2sin(2x+π/4) 1-cos2x+sin2x为什么变成--根号2sin（2x-π/4）+1 cos2X/sin(x-pai/4)=负根号2/2 计算COSX+SINX