f(x)=1\3x^3-a\2x^2+2x+1,f‘(x)=x^2-ax^2+2,x=[a±√(a²-8)]/2,∵0＜x1＜1＜x2＜3,∴0＜[a-√(a²-8)]/2＜1,1＜[a+√(a²-8)]/2＜3,得3＜a＜11/3.∵|x1-x2|=√(a²-8)],∴1＜|x1-x2|＜7/3,∵|x1-x...