解:圆(x-2)²+y²=3的参数方程:x=2+√3costy=√3sint所以y-x=√3sint-2-√3cost=√6(√2/2sint-√2/2cost)-2=√6(cosπ/4sint-sinπ/4cost)-2=√6sin(t-π/4)-2因为-1≤sin(t-π/4)≤1所以当sin(t-π/4)=1时,取得最大值y-x=√6-2当sin(t-π/4)=-1时,取得最小值y-x=-√6-2