=2sin(x+)-[sin(x+)+ cos(x+)]
=[sin(x+)-12cos(x+)]
=sin(x-).
对称轴为x-=kπ+(k∈Z
x=kπ+(k∈Z
x-=kπ(k∈Z
∴对称中心的坐标为(kπ+,0).
答案: