∵x>2 ∴x-2>0 y=(x²-2x+4)/x-2 =（x-2)²/(x-2)+3/x+2 =(x-2)+3/(x-2) ≥2√[3(x-2)/(x-2)] =2√3 当且仅当x-2=3/(x-2)即x=2+√3时取“=”号.
