f(x)=sinx+cos(x-π/6)
=sinx+√3/2cosx+1/2sinx
=3/2sinx+√3/2cosx
=√3(√3/2sinx+1/2cosx)
=√3sin(x+π/6)
因为sin（x+π/6）最大值为1
f(x)最大值为√3