f(x)=x/(x^2-x+3) 设a=x^2-x+3 a>0f'(x)=(3-x^2)/a^2 f'(x)=0 得x=±√3 所以f(x)在(-无穷,-√3)和(√3,﹢无穷)为减 (-√3,√3)为增∴f(x)min=f(-√3)=-1/(2√3-1) f(x)max=1/(2√3-1)∴值域为[-1/(2√3-1),1/(2√3-...