周期T=2π/2=π
2x-π/6=kπ
x=kπ/2+π/12
所以对称中心(kπ/2+π/12,0)
2x-π/6=kπ+π/2
x=kπ/2+π/3
所以对称轴x=kπ/2+π/3
2x-π/6=2kπ+π/2
x=kπ+π/3
2x-π/6=2kπ-π/2
x=kπ-π/6
所以
x=kπ+π/3,y最小=1
x=kπ-π/6,y最大=5