2x-π/3=kπ+π/2,x=kπ/2+5π/12 对称中心(kπ/2+5π/12,0)
2x-π/3=kπ,对称轴方程x=kπ/2+π/6,
2x-π/3=2kπ,x=kπ+π/6时,y最小=1
2x-π/3=2kπ+π,x=kπ+2π/3时,y最大=5