y=cos(x- π/6)[√3sin(x-π/6)+cos(x- π/6)]
=2cos(x- π/6)[(√3/2)*sin(x-π/6)+(1/2)*cos(x- π/6)] （两角和的正弦公式）
=2cos(x- π/6)*sin(x-π/6+π/6)
=2cos(x- π/6)sinx (积化和差公式)
=sin(x+x-π/6)+sin[x-(x- π/6)]
=sin(2x-π/6)+1/2
则当2x-π/6=2kπ+π/2,k∈Z时,函数y有最大值为3/2,
此时相应的自变量x的集合为：｛x | x=kπ+π/3,k∈Z｝