p＝m²+mn+n²-m-n+2→m²+(n-1)m+(n²-n+2-p)＝0.△1＝(n-1)²-4(n²-n+2-p)≥0→3n²-2n+(7-4p)≤0.△2＝4-12(7-4p)≥0→p≥5/3.逐步代回,知m＝n＝1/3时,所求最小值为：5/3....